5 exercises — read the technical sentence and choose the acronym that fits. Each question tests whether you know what an acronym means and when it's used in real engineering contexts.
Strategy for fill-in questions:
Read the whole sentence first — context clues narrow down the category (security, ops, design, metrics…)
Eliminate options whose meaning doesn't fit the context, not just ones you don't recognise
Check the explanation after each question — the wrong answers are just as useful to learn as the right ones
0 / 5 completed
1 / 5
Fill in the blank with the correct acronym:
"Our ___ pipeline automatically runs the test suite, builds the Docker image, and deploys to the staging environment on every merge to main."
CI/CD (Continuous Integration / Continuous Delivery or Deployment) — the practice of automating build, test, and deployment steps on every code change.
CI — Continuous Integration: automatically build and test every commit, catching issues early before they reach main. CD — Continuous Delivery: the release artifact is always production-ready; deployment to production is triggered manually. CD — Continuous Deployment: every passing build is automatically deployed to production with no manual step.
Why not the others? • SSL (Secure Sockets Layer) — now superseded by TLS; encrypts HTTP traffic • VPN (Virtual Private Network) — encrypts network traffic between devices • RBAC (Role-Based Access Control) — a permission model where access is granted by role
2 / 5
Fill in the blanks with the correct pair of acronyms:
"Our disaster recovery plan specifies two targets: ___ is how quickly we must restore service after an outage; ___ is how much data we can afford to lose measured in time."
RTO and RPO — two fundamental disaster recovery metrics:
• RTO (Recovery Time Objective) — the maximum acceptable time it takes to restore a service after a failure. "We must be back online within 4 hours" → RTO = 4 hours. • RPO (Recovery Point Objective) — the maximum acceptable amount of data loss measured in time. "We can lose at most 1 hour of data" → RPO = 1 hour → backups every ≤1 hour.
Memory tip: RTO = "Time to repair/restore"; RPO = "Point in time to recover to" (i.e., how old your backup can be).
Why not the others? • SLA (Service Level Agreement) — the contractual commitment to a customer about uptime/performance • SLO (Service Level Objective) — an internal target, e.g. 99.9% availability • MTTR (Mean Time To Repair) — average time to fix an incident • MTBF (Mean Time Between Failures) — average time between incidents
3 / 5
Fill in the blank with the correct acronym:
"After the breach, we reviewed our ___ system. Every admin API call, permission change, and data access is now logged, correlated in real time, and linked to automated alerts."
SIEM (Security Information and Event Management) — a platform that collects, aggregates, and correlates security log data from across an organisation's infrastructure, and generates alerts when suspicious patterns are detected.
Core SIEM capabilities: • Log aggregation — centralise logs from many systems • Correlation rules — detect multi-step attack patterns (e.g. brute force then login from new country) • Alerting — notify security teams in real time • Auditability — produce evidence trails for forensics and compliance
Why not the others? • CDN (Content Delivery Network) — distributes static assets close to users for faster load times • ORM (Object-Relational Mapper) — maps database rows to programming language objects (e.g. Hibernate, ActiveRecord) • DRY (Don't Repeat Yourself) — a software design principle, not a tool or system
4 / 5
Fill in the blank with the correct acronym:
"By following ___ principles, our classes each have a single responsibility, and each is open for extension but closed for modification."
SOLID — five object-oriented design principles coined by Robert C. Martin ("Uncle Bob") to make software more maintainable, flexible, and scalable:
• Single Responsibility Principle — a class should have only one reason to change • Open/Closed Principle — open for extension, closed for modification (add new behaviour by extending, not editing) • Liskov Substitution Principle — subtypes must be substitutable for their base types without breaking correctness • Interface Segregation Principle — prefer small, specific interfaces over large, general-purpose ones • Dependency Inversion Principle — depend on abstractions, not on concrete implementations
The clue in the sentence: "single responsibility" = S, and "open for extension but closed for modification" = O — these are two of the five SOLID letters.
Why not the others? • YAGNI — avoid adding features before they're needed • DRY — avoid code duplication • KISS — favour simplicity over complexity
5 / 5
Fill in the blank with the correct acronym:
"The growth team tracks ___ to understand retention: how many unique users open the app on any given day, and how many open it at least once per month."
DAU/MAU (Daily Active Users / Monthly Active Users) — two key product engagement metrics:
• DAU — the count of unique users who perform at least one meaningful action in the app on a given day • MAU — the count of unique users who perform at least one meaningful action in a 30-day rolling window • DAU/MAU ratio (stickiness) — what percentage of monthly users come back daily. A ratio above 20% is generally considered good; elite social/messaging apps exceed 50%.
Typical usage in engineering and product conversations: "Our DAU is 250k but MAU is 1.2M — our stickiness is around 21%." "The new home feed redesign increased DAU by 8% week-over-week."
Why not the others? • ROI (Return on Investment) — financial metric: (gain − cost) / cost • OKR (Objectives and Key Results) — goal-setting framework: an objective + 2–5 measurable key results • RPS (Requests Per Second) — server throughput metric