MRR / ARRMonthly / Annual Recurring Revenue
ChurnCustomers leaving
CACCustomer Acquisition Cost
LTV / CLVLifetime Value
LTV:CAC RatioThe efficiency test
Payback PeriodTime to recover acquisition cost
NRRNet Revenue Retention
ACV / TCVAnnual / Total Contract Value
FunnelThe path to becoming a customer
Conversion RateHow many take the next step
MQL / SQLMarketing / Sales Qualified Lead
ICPIdeal Customer Profile
TAM / SAM / SOMTotal / Serviceable Addressable Market, Serviceable Obtainable Market
GTMGo-To-Market
PLGProduct-Led Growth
FreemiumFree tier plus paid upgrade
OnboardingGetting users to first value
ActivationThe first real success
RetentionCustomers who stay
Cohort AnalysisGrouping by start date
NPSNet Promoter Score
KPIKey Performance Indicator
OKRObjectives and Key Results
SEOSearch Engine Optimisation
PPC / SEMPay Per Click / Search Engine Marketing
CTACall To Action
A/B TestComparing two versions
AttributionWhich effort produced the sale
Upsell / Cross-sellGrowing existing accounts
CRMCustomer Relationship Management
CMSContent Management System
USP / UVPUnique Selling Proposition / Unique Value Proposition
DAU / WAU / MAUDaily / Weekly / Monthly Active Users
ARPU / ARPAAverage Revenue Per User / Account
North Star MetricPrimary product value metric
Unit EconomicsPer-customer business economics

10 · 19 terms

Commercial & Contracts

The terms that shape deals, responsibilities and business relationships.

B2B / B2C / B2B2CWho you sell to
RFP / RFI / ITTRequest for Proposal / Information, Invitation to Tender
PQQ / SQPre-Qualification Questionnaire / Selection Questionnaire
Framework AgreementPre-approved supplier list
FTSFind a Tender Service
SOWStatement of Work
MSAMaster Service Agreement
NDANon-Disclosure Agreement
SLAService Level Agreement
IPIntellectual Property
White LabelRebranded for a partner
PilotA paid or limited first deployment
ProcurementThe buying process
Per-seat / Usage-based pricingTwo common models
Vendor Lock-inDifficulty leaving
ROIReturn on Investment
TCOTotal Cost of Ownership
CapEx / OpExCapital Expenditure / Operating Expenditure
FinOpsTechnology financial operations practice

11 · 18 terms

AI in Development

The fast-moving language of AI-assisted software work.

AI / MLArtificial Intelligence / Machine Learning
LLMLarge Language Model
PromptThe instruction you give an AI
TokenHow AI text is measured
Context WindowHow much the model can hold
HallucinationConfident but wrong output
RAGRetrieval-Augmented Generation
Fine-tuningAdapting a model
AI Agent / AgenticAI that takes actions
MCPModel Context Protocol
EmbeddingsNumerical semantic representations
Vector DatabaseEmbedding search database
InferenceRunning a trained model
EvalsModel evaluations
GuardrailsAI safety controls
Prompt InjectionLLM application vulnerability
MultimodalMultiple input or output modes
MLOpsMachine Learning Operations

12 · 24 terms

Product, UX & User Research

How teams understand people, shape useful products and test decisions before scaling them.

Product StrategyHow a product will create value and win
Product VisionThe intended future state of a product
Product DiscoveryLearning what problem and solution are worth pursuing
Problem StatementA focused description of the problem to solve
Opportunity Solution TreeA map from desired outcome to opportunities and solutions
User NeedAn outcome a user must achieve
Jobs to Be Done (JTBD)Jobs to Be Done
PersonaA research-informed representation of a user group
User JourneyThe steps and touchpoints in a user's experience
Journey MapA visual map of a user journey
Service BlueprintA map of frontstage and backstage service activity
WireframeA low-detail interface layout
MockupA realistic static representation of a design
Design SystemReusable design rules, components and guidance
Design TokenA named design decision stored as data
Information ArchitectureThe structure and labelling of information
Interaction DesignDesigning how people act and receive feedback
Content DesignDesigning content around user needs
Usability TestingObserving people attempt realistic tasks
User InterviewA structured conversation with a user
Contextual InquiryInterviewing and observing people in context
Diary StudyResearch recorded by participants over time
Card SortingGrouping and naming content with participants
Feature AdoptionUse of a feature by its intended audience

13 · 24 terms

Testing & Quality

The methods and evidence used to find risk and build confidence in software.

Unit TestA test of a small unit of code
Integration TestA test of components working together
End-to-End Test (E2E)End-to-End Test
Regression TestingChecking that existing behaviour still works
Smoke TestA broad check of essential functions
Sanity TestA focused check after a small change
Acceptance TestA test against agreed business expectations
Test CaseA defined input, action and expected result
Test SuiteA grouped collection of tests
Test FixtureA known setup used by tests
Test DoubleA substitute for a real dependency in a test
MockA test double that verifies interactions
StubA test double that returns prepared answers
Test CoverageThe scope exercised by testing
Code CoverageThe proportion of code executed by tests
Test-Driven Development (TDD)Test-Driven Development
Behaviour-Driven Development (BDD)Behaviour-Driven Development
Static AnalysisExamining code without running it
Dynamic AnalysisExamining software while it runs
Load TestingTesting under expected or rising demand
Stress TestingTesting beyond normal operating limits
Performance TestingMeasuring speed, capacity and stability
Fuzz TestingTesting with generated or malformed inputs
Mutation TestingChecking tests by deliberately changing code

14 · 12 terms

Accessibility & Inclusive Design

Designing digital experiences that work for disabled people and a wider range of human needs.

Accessibility (A11y)Accessibility
WCAGWeb Content Accessibility Guidelines
Assistive TechnologyTechnology that supports access and participation
Screen ReaderSoftware that presents screen content as speech or braille
Keyboard NavigationUsing an interface without a pointing device
Focus OrderThe sequence followed by keyboard focus
Colour ContrastThe visual difference between foreground and background
Alternative Text (Alt Text)A text alternative for non-text content
CaptionsText for speech and meaningful audio
ARIAAccessible Rich Internet Applications
Semantic HTMLHTML chosen for meaning, not appearance
Inclusive DesignDesigning with human diversity in mind

15 · 24 terms

Architecture & Distributed Systems

The structures and patterns used to design systems that span components, services and machines.

System ArchitectureThe high-level structure of a software system
Distributed SystemA system whose components run on multiple computers
N-tier ArchitectureAn application split into logical tiers
Layered ArchitectureSoftware organised into responsibility layers
Hexagonal ArchitecturePorts and Adapters architecture
Clean ArchitectureArchitecture with dependencies pointing inward
Domain-Driven Design (DDD)Domain-Driven Design
Bounded ContextA boundary within which a domain model is consistent
Service-Oriented Architecture (SOA)Service-Oriented Architecture
CQRSCommand Query Responsibility Segregation
Event SourcingStoring state as an ordered sequence of events
Saga PatternA distributed transaction made of local steps
Circuit BreakerStopping calls to a failing dependency
Bulkhead PatternIsolating resources to contain failure
Retry PatternRepeating an operation after a transient failure
IdempotencyThe same request can be repeated without extra effect
Eventually ConsistentReplicas converge after a delay
Strong ConsistencyReads reflect the latest completed write
CAP TheoremConsistency, Availability and Partition tolerance
Sidecar PatternA helper process deployed beside an application
Strangler Fig PatternIncrementally replacing a legacy system
Backends for Frontends (BFF)Backends for Frontends
API CompositionCombining data from multiple services
Choreography / OrchestrationTwo ways to coordinate distributed work

16 · 24 terms

Reliability, Platform & Developer Experience

Keeping services dependable while making the supported path easier for engineering teams.

Site Reliability Engineering (SRE)Site Reliability Engineering
Platform EngineeringBuilding internal platforms for delivery teams
Internal Developer Platform (IDP)Internal Developer Platform
Developer Experience (DevEx / DX)Developer Experience
Golden PathA supported route for a common engineering task
Self-ServiceUsers obtain a capability without a manual hand-off
ToilRepetitive manual operational work
Incident CommanderThe person coordinating an incident response
Escalation PolicyRules for involving additional responders
Blameless CultureLearning from failure without scapegoating
Alert FatigueReduced attention caused by too many alerts
PagerA system that notifies the on-call responder
PlaybookA guide for handling a known operational scenario
Service CatalogueA discoverable inventory of internal services
Health CheckA check that a service can perform its role
Synthetic MonitoringScripted checks that simulate user activity
Real User Monitoring (RUM)Real User Monitoring
Distributed TracingFollowing one request across services
LoggingRecording discrete events from a system
MetricsNumeric measurements collected over time
TelemetryData emitted to understand a system
Capacity PlanningForecasting resources needed for demand
Chaos EngineeringTesting resilience through controlled failure
Game DayA rehearsed operational scenario

17 · 24 terms

Data Engineering, Analytics & Governance

Moving, modelling, cataloguing and governing data so it remains useful and trustworthy.

Data EngineeringBuilding reliable systems for data
Data PipelineA sequence that moves and transforms data
Data IngestionBringing data into a system
Batch ProcessingProcessing a bounded collection of data
Stream ProcessingProcessing events as they arrive
Change Data Capture (CDC)Change Data Capture
Data LakehouseA platform combining lake and warehouse ideas
Data MartA focused analytical data store
Operational Data Store (ODS)Operational Data Store
Data MeshDecentralised, domain-oriented data ownership
Data FabricAn integrated layer for managing distributed data
Data ProductData delivered with an accountable product mindset
Data ContractAn agreement about a data interface
Data LineageThe history and movement of data
Data CatalogueA searchable inventory of data assets
MetadataData that describes other data
Master Data Management (MDM)Master Data Management
Data QualityFitness of data for its intended use
Data GovernanceDecision rights and controls for data
Data StewardA person accountable for a data domain
SchemaThe defined structure of data
Schema RegistryA managed store of data schemas
OLTPOnline Transaction Processing
OLAPOnline Analytical Processing

18 · 18 terms

Privacy, Compliance & Responsible AI

Protecting people, meeting obligations and governing automated systems with care.

Personal DataInformation relating to an identifiable person
Special Category DataPersonal data requiring extra protection
Data ControllerThe organisation deciding why and how personal data is used
Data ProcessorA party processing personal data for a controller
Lawful BasisA legal justification for processing personal data
Consent ManagementRecording and respecting people's choices
Data MinimisationUsing only the personal data that is needed
Purpose LimitationUsing personal data only for specified purposes
Data RetentionHow long information is kept
Right to ErasureA person's right to request deletion in certain cases
Subject Access Request (SAR)Subject Access Request
DPIAData Protection Impact Assessment
Privacy by DesignBuilding privacy into design and operation
PseudonymisationReplacing identifiers while keeping a separate key
AnonymisationRemoving identifiability beyond reasonable reversal
Model CardStructured documentation about an AI model
AI Impact AssessmentA structured assessment of an AI system's effects
Human-in-the-loop (HITL)Human-in-the-loop

19 · 18 terms

People, Roles & Team Language

The responsibilities and titles you will hear across modern multidisciplinary technology teams.

Product ManagerOwns product direction and outcomes
Product OwnerMaintains value and backlog priorities
Delivery ManagerImproves how work moves through a team
Engineering ManagerLeads engineers and engineering delivery
Technical Lead (Tech Lead)Provides technical direction for a team
Staff EngineerA senior individual-contributor engineer
Solutions ArchitectDesigns solutions for specific needs
Enterprise ArchitectAligns technology across an organisation
Site Reliability EngineerAn engineer focused on reliable services
Platform EngineerAn engineer building internal platforms
Data EngineerAn engineer building data systems
Machine Learning EngineerAn engineer productionising machine learning
Security EngineerAn engineer reducing technology risk
QA EngineerQuality Assurance Engineer
User ResearcherStudies users and their needs
Content DesignerDesigns clear content around user needs
Developer AdvocateConnects developers with a product or platform
Chief Technology Officer (CTO)Chief Technology Officer

20 · 18 terms

Startup Finance & SaaS Operations

The financial measures and funding mechanics behind recurring-revenue companies.

Gross MarginRevenue remaining after direct delivery costs
Contribution MarginRevenue remaining after variable costs
Burn MultipleNet cash burn divided by net new ARR
Magic Number (SaaS)A measure of sales and marketing efficiency
Rule of 40Growth rate plus profit margin
Revenue ChurnRecurring revenue lost from existing customers
Logo ChurnCustomer accounts lost
Expansion RevenueAdditional revenue from existing customers
Contracted ARR (CARR)Contracted Annual Recurring Revenue
BookingsValue of contracts signed in a period
BillingsAmounts invoiced to customers
Deferred RevenueCash billed or received before revenue is earned
Cash FlowMovement of cash into and out of a business
Break-evenThe point where revenue covers costs
Default AliveLikely to reach profitability before cash runs out
Bridge RoundInterim financing between larger rounds
Down RoundA funding round at a lower valuation
Liquidation PreferenceInvestor priority in distributing exit proceeds

21 · 18 terms

Sales, Customer Success & RevOps

How technology businesses create pipeline, close work, retain customers and align revenue teams.

Revenue Operations (RevOps)Revenue Operations
Sales OperationsProcesses and systems supporting sales
Customer Success (CS)Helping customers realise intended value
Customer Success Manager (CSM)Customer Success Manager
Account Executive (AE)Account Executive
Sales Development Representative (SDR)Sales Development Representative
Business Development Representative (BDR)Business Development Representative
Account-Based Marketing (ABM)Account-Based Marketing
Product-Qualified Lead (PQL)Product-Qualified Lead
Lead ScoringRanking leads by fit and intent
Sales PipelineOpen sales opportunities by stage
Sales ForecastAn estimate of future sales outcomes
Sales CycleTime and steps from prospect to customer
Proof of Value (PoV)Proof of Value
Customer Health ScoreA combined signal of account health
Quarterly Business Review (QBR)Quarterly Business Review
Renewal RateThe share of customers or contracts renewed
Land and ExpandStart small, then grow within an account

22 · 34 terms

Networks, Infrastructure & Edge

How traffic is addressed, routed, protected and delivered across connected systems.

IP AddressInternet Protocol address
IPv4 / IPv6Internet Protocol version 4 / version 6
TCP / UDPTransmission Control Protocol / User Datagram Protocol
PortA numbered network service endpoint
SubnetA logical subdivision of an IP network
CIDRClassless Inter-Domain Routing
VPC / VNetVirtual Private Cloud / Virtual Network
VPNVirtual Private Network
NATNetwork Address Translation
FirewallA control that filters network traffic
Proxy / Reverse ProxyIntermediaries for client or server traffic
TLS / SSLTransport Layer Security / Secure Sockets Layer
Certificate Authority (CA)Certificate Authority
Public Key Infrastructure (PKI)Public Key Infrastructure
Domain NameA human-readable name in the Domain Name System
NameserverA server that answers DNS queries
Edge ComputingProcessing closer to users or data sources
AnycastOne IP address announced from multiple locations
LatencyDelay between an action and its response
Bandwidth / ThroughputCapacity versus achieved transfer rate
Host / HostnameA machine and the name that identifies it
Apex Domain / Zone ApexTop name in a DNS zone
CNAME RecordCanonical Name record
TXT RecordText record
A / AAAA RecordIPv4 / IPv6 address records
MX RecordMail Exchange record
TTLTime to Live
DNS ZoneAdministrative portion of the DNS namespace
DNS PropagationDelay while cached DNS data expires
DNSSECDomain Name System Security Extensions
SubdomainDomain below another domain
FQDNFully Qualified Domain Name
PTR / Reverse DNSPointer record / address-to-name lookup
SPF / DKIM / DMARCEmail authentication and policy controls

23 · 32 terms

Linux, Servers & Web Hosting

The operating-system, hosting and web-server language used to run and maintain internet services.

cron / Cron JobTime-based job scheduler
sudoRun a command with another user's privileges
NGINXWeb server and reverse proxy
UFWUncomplicated Firewall
SSHSecure Shell
UptimeTime a service remains available
Root User / SuperuserHighest-privilege system account
VPSVirtual Private Server
Linux Distribution / DistroPackaged Linux operating-system release
Shell / BashCommand interpreter / Bourne-Again Shell
systemdLinux system and service manager
Daemon / ServiceLong-running background program
Process / PIDRunning program / Process Identifier
APT / Package RepositoryAdvanced Package Tool / package source
File PermissionsRead, write and execute access rules
chmod / chownChange mode / change owner
Environment VariableNamed value supplied to a process
Log File / Log RotationRecorded events / managed log rollover
SCP / SFTPSecure Copy / SSH File Transfer Protocol
rsyncIncremental file-transfer utility
Root Directory (/)Top of a Unix-like filesystem
localhostName for the local machine
Web ServerSoftware that handles web requests
Apache HTTP ServerOpen-source web server
PHP-FPMPHP FastCGI Process Manager
LAMP / LEMP StackLinux, Apache or NGINX, MySQL or MariaDB, PHP
Virtual Host / Server BlockPer-site web-server configuration
Document Root / Web RootDirectory containing published site files
FastCGIFast Common Gateway Interface
HTTP Status CodeThree-digit result of an HTTP request
Redirect / Rewrite RuleMove a client / internally remap a request
Let's Encrypt / CertbotCertificate authority / certificate automation client

24 · 14 terms

Events, Conferences & Community

The formats, roles and artefacts used to exchange knowledge and build professional communities.

SymposiumA focused meeting for expert discussion
ConferenceA structured multi-session professional event
MeetupAn informal community gathering
HackathonA time-boxed collaborative build event
WebinarA seminar delivered online
WorkshopAn interactive learning or problem-solving session
KeynoteA headline talk setting the event's theme
Panel DiscussionA moderated conversation among several speakers
Fireside ChatAn informal interview-style conversation
Lightning TalkA very short focused presentation
Call for Papers (CfP)Call for Papers
SpeakerA person presenting at an event
Speaker RosterThe maintained list of event speakers
Sponsor / ExhibitorCommercial supporter / showcasing organisation

25 · 14 terms

Collaboration, Meetings & Knowledge Work

The tools and practices used to communicate, decide and preserve shared knowledge.

Microsoft TeamsMicrosoft's collaboration and communications platform
Zoom WorkplaceZoom's collaboration platform
NotionNotion's connected workspace
SlackSlack's work communication platform
Asynchronous WorkCollaboration without everyone participating at once
Synchronous WorkCollaboration happening at the same time
Video ConferenceA live meeting using networked audio and video
Instant MessagingReal-time text-based communication
ChannelA named space for group communication
WorkspaceA shared digital environment for a group
WikiA collaboratively edited knowledge site
Knowledge BaseAn organised collection of reusable information
Meeting MinutesThe formal record of a meeting
Action ItemA specific follow-up task from a discussion

26 · 10 terms

Documents, Formats & Content Exchange

The file formats and standards that let information move safely between tools and organisations.

PDFPortable Document Format
MarkdownLightweight plain-text markup
CSVComma-Separated Values
XMLExtensible Markup Language
YAMLYAML Ain't Markup Language
Rich Text Format (RTF)Rich Text Format
OpenDocument Format (ODF)OpenDocument Format
Office Open XML (OOXML)Office Open XML
MIME TypeMultipurpose Internet Mail Extensions media type
Digital SignatureCryptographic proof attached to data

27 · 6 terms

AI Ecosystem: Companies, Models & Products

Named commercial actors and products, clearly separated from universal AI concepts.

OpenAIAI research and deployment company
AnthropicAI safety and research company
ChatGPTOpenAI's conversational AI assistant
ClaudeAnthropic's AI assistant
CodexOpenAI's coding agent
GeminiGoogle's AI assistant and model family