ReturnNull

Software Developer, Craftsman

[Umesh Kumar Yadav @Umesh__digital]

DSA Preparation Roadmap (From Zero to OA Ready)

1. Sliding Window: 3, 76, 209, 424, 567, 904
2. Two Pointers: 11, 15, 16, 18, 42, 167
3. Fast/Slow Pointers (Linked List): 141, 142, 19, 876, 160, 234
4. Binary Search on Sorted Data: 33, 34, 35, 153, 162, 704
5. Binary Search on Answer: 875, 1011, 410, 774, 1283, 1482
6. Hashing / Frequency Maps: 1, 49, 128, 217, 242, 347
7. Prefix Sum / Running Sum: 303, 560, 724, 930, 974, 523
8. Difference Array / Range Updates: 370, 1094, 1109, 1893, 1943, 2381
9. Monotonic Stack: 739, 496, 503, 84, 85, 901
10. Monotonic Queue / Deque: 239, 862, 1425, 1438, 1499, 1696
11. Heap / Top K: 215, 347, 692, 703, 973, 1046
12. Intervals: 56, 57, 252, 253, 435, 452
13. Greedy Scheduling / Sorting: 45, 55, 406, 621, 763, 134
14. Linked List Manipulation: 21, 23, 24, 25, 92, 138
15. Tree DFS: 104, 112, 113, 543, 124, 226
16. Tree BFS / Level Order: 102, 103, 199, 515, 637, 116
17. BST Problems: 98, 99, 230, 235, 450, 700
18. Backtracking Basics: 46, 47, 77, 78, 90, 39
19. Backtracking with Constraints: 40, 17, 79, 131, 51, 52
20. Graph BFS / DFS: 200, 695, 733, 994, 1091, 1254
21. Topological Sort / DAG: 207, 210, 802, 1462, 1203, 2115
22. Union Find / DSU: 547, 684, 1319, 1579, 990, 1202
23. Shortest Path: 743, 787, 1514, 1631, 1334, 1976
24. MST / Graph Greedy: 1584, 1135, 1168, 1489, 778, 1102
25. Trie: 208, 211, 212, 648, 677, 1268
26. Bit Manipulation: 136, 137, 191, 338, 268, 190
27. 1D DP Basics: 70, 198, 213, 322, 279, 300
28. Knapsack / Subset DP: 416, 494, 518, 474, 1049, 879
29. Grid DP: 62, 63, 64, 221, 931, 120
30. String DP / Sequence DP: 1143, 72, 115, 583, 97, 1312

How to use this list?
- These numbers are Leetcode problem numbers
- Do 3 patterns at a time, not all 30 together.
- For each pattern, solve the first 2 to understand the idea, the next 2 to get repetition, and the last 2 to stretch yourself.
- After every pattern, write one reusable template from memory.
- Do not just “solve and move on.” Ask: what signal in the question pointed to this pattern?
- If you get stuck, revisit the same pattern after 3 to 4 days. Pattern recognition is built by spacing, not cramming.

[Jason Zook @jasondoesstuff]

Step 1: Tell Claude Code to create a "design-system.md" from your current app/project

Step 2: Tell it to install Remotion

Step 3: Tell it to make motion graphics of interactions in your app using the design system it created (I did 16:9 for YouTube b-roll).

😎💥💪

You can also tell it to mock up popular apps (like Slack in the example below).

[Cap-EO 👨🏾‍💻 @EOEboh]

As a backend engineer, you should be able
to explain these concepts without Googling:

- What happens during an HTTP request lifecycle
- The difference between authentication and authorization
- Why indexes speed up reads but slow down writes
- What a database transaction actually guarantees
- How connection pooling works and why it matters
- The difference between sync and async processing
- What idempotency means and why payments need it
- How a JWT is structured and verified

How many can you explain right now?

[Kaka Ruto @kaka_ruto]

And today we launch a clean 3-part stack for secure code execution in isolated containers

- runbox (core API)
- runbox-py (Python SDK)
- runbox-rb (Ruby SDK)

I needed to run ai-generated code safely, keep it fast enough for real product UX, and avoid rebuilding infra every single time, so I built this

[CLEAN CAR CLUB @TheCleanCarClub]

Car Umbrella Hook

[Intermood @Intermoodd]

This retro TV stand is seriously so cool

[Tom Dörr @tom_doerr]

Android phone as an SMS gateway via HTTP API

https://t.co/4lVE2E8IQ9

[Daisy Faith Auma 🇰🇪🇬🇧 @daisyfaithauma]

2 days until Night of Code! 🔥

📅 Friday, February 27
📍 LuxDevHQ Offices, 1 Kanyangia Drive, Garden Court D18A
🕡 6:30 PM - 1:00 AM

Real projects. Real skills. Real industry exposure.

Secure your spot: https://t.co/YZd632s7VZ

[SumitM @SumitM_X]

As a developer,

Please Slap yourself if you are unable to explain even 10 from below terms :

Indexing
Clustering
Denormalization
Normalization
Read replicas
Leader–Follower replication
Multi-leader replication
Quorum
Consensus
CAP theorem
BASE
ACID
Eventual consistency
Strong consistency
Snapshot isolation
MVCC (Multi-Version Concurrency Control)
Two-phase commit (2PC)
Three-phase commit (3PC)
Write-ahead logging (WAL)
Checkpointing
Compaction
Rebalancing
Resharding
Data locality
Hot partition
Split-brain
Failover
High availability (HA)
Horizontal scaling
Vertical scaling
Load balancing
Connection pooling
Caching
Materialized views
Secondary indexes
Composite index
Covering index
Bloom filter
LSM tree
B-tree
Query planner
Cost-based optimizer
Deadlock
Lock escalation
Optimistic locking
Pessimistic locking
Dirty read
Phantom read
Read skew
Write skew
Data skew
Backpressure
Circuit breaker
Throttling
Rate limiting
CDC (Change Data Capture)
Logical replication
Physical replication
Geo-replication
Federation
Data lake
Data warehouse
Columnar storage
Row-based storage
Time-series partitioning
Hash partitioning
Range partitioning
Consistent hashing
Data migration
Schema evolution
Schema registry
Idempotency
Exactly-once semantics

[Tom Dörr @tom_doerr]

Dashboard for local git repositories

https://t.co/ecOyvPJoef

[Adi @AdityaSur11]

Subscription Calendar Animation
Made in figma
Thoughts?

[Nick Babich @101babich]

🔥Top 7 MCPs worth adding to your workflow

MCP (Model Context Protocol) connects AI coding tools to the services you already use like Figma, Notion, Google Analytics, and more.

1️⃣ context7 (Pulls live library docs into your AI tool so it codes with the right context)
2️⃣ NotebookLM MCP (Feeds your research and specs directly to AI, so it builds with real user needs in mind)
3️⃣ shadcn/UI MCP (Gives AI actual component knowledge instead of letting it guess your UI)
4️⃣ Figma MCP (Turns your designs into code using real layout structure, not screenshots)
5️⃣ Notion MCP (Lets AI read your PRDs, pull specs, and update tasks without leaving the editor)
6️⃣ Google Analytics MCP (Query your GA4 data in plain English to validate design decisions fast)
7️⃣ Supabase MCP (Set up your entire backend through natural language. No SQL needed.)

👇

[David Amunga ⚡️ @davidamunga_]

GH repo →
https://t.co/3AEad2o4ZX

[DHH @dhh]

Next version of Omarchy will color coordinate the Asus ROG RGB keyboard backlighting with your chosen theme.

[Maestro @maestro__dev]

this is what AUTOMATED UI testing looks like

testing @Twitch's with Maestro

[Mrinal @Hi_Mrinal]

I had my interview as a Backend engineer at a startup from Hungary

Built a simple place for managing all my cron jobs related to httpbin webhook, built this during the call while explaining what it can be stretched to and how can I do that

for now its a monorepo and built on go, rabbitmq and tanstack has been used for the frontend

[Akhilesh Mishra @livingdevops]

You are not a Cloud Architect if you are just:
❌ Deploying apps to AWS/Azure
❌ Using managed services like RDS or Lambda
❌ Following tutorials to spin up infrastructure
❌ Clicking through cloud consoles
❌ Copy-pasting Terraform from Stack Overflow

You are a Cloud Architect if you are:
✅ Designing multi-region failover strategies
✅ Building cost-optimized infrastructure at scale
✅ Creating security frameworks and compliance strategies
✅ Planning disaster recovery with RTO/RPO targets
✅ Capacity planning for unpredictable growth
✅ Making trade-off decisions between services (and defending them)
✅ Designing network architecture (VPCs, subnets, peering, gateways)
✅ Writing enterprise-level IaC with modules and state management

Cloud engineers deploy to the cloud.
Cloud Architect: Designs systems for scale, cost, security, and resilience

[Lloyd 👨‍💻 @lloydtheophilus]

Senior DevOps Engineer Interview Questions

The panel focused heavily on Kubernetes, Helm, Jenkins, AWS, Terraform, Prometheus & Grafana — all scenario-based and practical.
Sharing the questions here so others preparing for similar roles can benefit ➡️

😬Kubernetes — Scenario-Based Questions
- Your Pod is restarting frequently. How do you identify the root cause?
- A Deployment is stuck in "progressing" state — how do you troubleshoot?
- How do you debug a CrashLoopBackOff issue?
- How do you check which Pods are consuming high memory or CPU?
- Node is in NotReady state — steps to investigate?
- Your application is not accessible through service — what will you check?
- How do you handle failed daemonset pods?
- Persistent Volume not attaching — what’s your troubleshooting approach?
- How do you perform rolling updates and rollbacks safely?
- How do you perform health checks for Pods and Nodes in live environments?

😬Helm — Practical Questions
- What are values.yaml and how do you override them?
- How do you manage multiple environment deployments using Helm?
- How do you debug a failed Helm release?
- What is the difference between Helm Chart, Release, and Repository?

😬Jenkins — CI/CD Questions
- Why choose Declarative Pipeline over Scripted Pipeline?
- How do you integrate SonarQube into a Jenkins pipeline?
- How do you build → containerize → push → deploy using Jenkins?

😬AWS — Scenario Questions
- Your EC2 instance is unreachable — how do you diagnose?
- How do you implement Auto Scaling with proper health checks?
- Difference between ALB and NLB and when to use which?
- S3 cross-region replication setup steps?
- How to troubleshoot high latency in API Gateway?
- How do you reduce RDS cost without downtime?
- What happens if Terraform state is deleted in S3?
- How do you secure your VPC workloads at scale?

😬Terraform — Infra as Code Questions
- How do you recover from a deleted Terraform state file?
- How do you create 50 EC2 instances with different configurations (dynamic blocks)?
- Share your screen and write a terraform code to create a VPC with all there components and create a RDS database into VPC.

😬Prometheus & Grafana — Monitoring Questions
- How do you set up custom metrics for Kubernetes pods?
- How do you troubleshoot missing data points in Grafana dashboards?
- How do you create alerts for high CPU or memory usage?

😬Reflection:
This interview round was entirely hands-on, scenario-focused, and tested how well you handle production-grade issues, automation thinking, and troubleshooting skills.
If you're preparing for DevOps/SRE roles — start practicing real scenarios, not definitions

[Sam Meech Ward @Meech_Ward]

postgres is the best database

[Maestro @maestro__dev]

this is what AUTOMATED end-to-end testing looks like ✨

testing @duolingo's user flow