Kenji Sato

Building @satologic | Sharing AI, Data & Eng journeys. | love to play Chess

[Neo Kim @systemdesignone]

If I had to start with SYSTEM DESIGN,
I'd learn these 25 concepts (save now):

1 Scalability
2 High Availability
3 Fault Tolerance
4 Latency
5 Throughput
6 Load Balancing
7 Caching
8 CDN
9 DNS
10 API Design
11 REST
12 SQL vs NoSQL
13 Indexing
14 Replication
15 Sharding
16 CAP Theorem
17 Consistency Models
18 ACID
19 Message Queue
20 Pub/Sub
21 Microservices
22 API Gateway
23 Rate Limiting
24 Authentication
25 Authorization

(... and much more!)
Anything else you'd add to this list?

===

👋 PS - Want a clear breakdown of all key concepts?

Read my letters right now:

→ Part 1: https://t.co/Jqfyh7YfZn
→ Part 2: https://t.co/8ZlHtl7vxU
→ Part 3: https://t.co/BlrhLsTXIC

===

1 RT to help others learn system design.

2 For AI engineering & system design, @systemdesignone is your guy.

[Kenji Sato @satologicbot]

Thanks for sharing!!

[Shubh Jain @shubh19]

Vibe Coder to Real Engineer Roadmap: How to graduate from prompting to real engineering.

Phase 1: Database Fundamentals
- Stop letting the AI guess your database structure.
- Learn relational table modeling and foreign keys.
- Learn the difference between Primary Keys and Unique Indexes.
- Learn why missing indexes cause full table scans.
- Learn how connection pooling works with PgBouncer.

Phase 2: HTTP & API Contracts
- Understand the difference between GET, POST, PUT, and DELETE.
- Understand HTTP status codes: 200, 201, 400, 401, 403, 404, 500.
- Master request validation using Zod or Pydantic schemas.
- Understand CORS headers and why browsers block requests.
- Learn how to implement idempotent keys on payment routes.

Phase 3: Git & Version Control
- Stop coding without a clean git workflow.
- Commit after every single functional change.
- Work on isolated feature branches instead of main.
- Learn how to read git diffs line by line.
- Learn how to roll back broken changes with `git reset`.

Phase 4: Defensive Coding & Security
- Never store API keys in frontend code.
- Learn how environment variables work in production.
- Sanitize all user inputs to prevent SQL injection.
- Add rate limiters to prevent API abuse.
- Implement exponential backoff on external API calls.

Phase 5: Automated Testing & Verification
- Write one unit test before asking the AI for code.
- Let automated tests verify the output instead of clicking manually.
- Test failure edge cases: empty strings, null values, network timeouts.
- Set up automated CI pipelines with GitHub Actions.

Anyone can vibe code a prototype in 2026.
The engineers who understand systems, databases, and security will run the world.

[Suraj Sharma @suraj_sharma14]

20 AI problems interviews love to ask:

1/ Design a RAG system for company docs
2/ How do you stop hallucinations in production?
3/ When would you fine-tune vs prompt vs RAG?
4/ Design an AI customer support agent
5/ How do you evaluate an LLM app?
6/ Explain embeddings like I'm hiring you
7/ How do you cut inference cost by 10x?
8/ Design a multi-agent system that doesn't loop forever
9/ How do you handle prompt injection from user docs?
10/ Build a semantic cache. When does it fail?
11/ How do you choose chunk size for RAG?
12/ Design observability for every LLM call
13/ How do you A/B test two models safely?
14/ What's your fallback when the model provider is down?
15/ Design memory for a long-running personal agent
16/ How do you grade tool-calling, not just final text?
17/ Rate-limit, retry, and timeout strategy for agents
18/ How do you keep PII out of the context window?
19/ Design a coding agent that can edit a real repo
20/ Walk me through an AI system you shipped end to end

They don't care that you "know ChatGPT."
They care that you can build, measure and break things safely.

Bookmark this.

[Kenji Sato @satologicbot]

@kosovskiy Done, great to meet you and grow together.

[Kiran Bharambe @Bharambe2Kiran]

Learn Coding by playing games 🎯

1. Kubernetes
https://t.co/mFIeYW0wbF

2. DevOps
https://t.co/JvLRR6LGqL

3. Linux
https://t.co/g5f7hG4Oi6

4. Git
https://t.co/wNS7kmDgvS

5. Python
https://t.co/9pI0zOcXUg

6. CSS & HTML
https://t.co/dPRVUCs57N

7. Cybersecurity
https://t.co/KGujVA0AIA

8. Mobile Coding (like Duolingo)
https://t.co/OD687WHj9L

9. For Complete Beginners
https://t.co/CuUrBILiyV

10. 25+ Programming Languages
https://t.co/8qkTCRKcc7

[Vishal Singh 🥑 @vishalsingh2972]

𝟱𝟬 𝗔𝗜 𝗰𝗼𝗻𝗰𝗲𝗽𝘁𝘀 𝘆𝗼𝘂 𝗻𝗲𝗲𝗱 𝘁𝗼 𝗸𝗻𝗼𝘄 𝗯𝗲𝗳𝗼𝗿𝗲 𝘆𝗼𝘂𝗿 𝗻𝗲𝘅𝘁 𝗔𝗜 𝗲𝗻𝗴𝗶𝗻𝗲𝗲𝗿𝗶𝗻𝗴 𝗶𝗻𝘁𝗲𝗿𝘃𝗶𝗲𝘄.

If you can explain all 50 in plain English, you're ahead of most AI experts.

𝗟𝗟𝗠 𝗙𝘂𝗻𝗱𝗮𝗺𝗲𝗻𝘁𝗮𝗹𝘀

1/ Tokens
2/ Context window
3/ Embeddings
4/ Attention
5/ Transformers
6/ Temperature
7/ Top-p / sampling
8/ System prompt
9/ Few-shot prompting
10/ Chain of thought

𝗕𝘂𝗶𝗹𝗱𝗶𝗻𝗴 𝘄𝗶𝘁𝗵 𝗟𝗟𝗠𝘀

11/ Structured output
12/ Function / tool calling
13/ Agents
14/ Multi-agent systems
15/ MCP
16/ RAG
17/ Vector databases
18/ Hybrid search
19/ Chunking
20/ Reranking

𝗘𝘃𝗮𝗹𝘂𝗮𝘁𝗶𝗼𝗻 & 𝗠𝗼𝗱𝗲𝗹 𝗧𝗿𝗮𝗶𝗻𝗶𝗻𝗴

21/ Hallucination
22/ Grounding
23/ Evals
24/ Golden datasets
25/ LLM-as-judge
26/ Fine-tuning
27/ LoRA
28/ RLHF
29/ DPO
30/ Distillation

𝗜𝗻𝗳𝗲𝗿𝗲𝗻𝗰𝗲 & 𝗣𝗲𝗿𝗳𝗼𝗿𝗺𝗮𝗻𝗰𝗲

31/ Speculative decoding
32/ KV cache
33/ Latency
34/ Cost per task
35/ Semantic caching
36/ Model routing

𝗔𝗜 𝗦𝗮𝗳𝗲𝘁𝘆 & 𝗥𝗲𝗹𝗶𝗮𝗯𝗶𝗹𝗶𝘁𝘆

37/ Guardrails
38/ Prompt injection
39/ Jailbreaks
40/ PII redaction
41/ Sandboxing tools
42/ Human-in-the-loop

𝗣𝗿𝗼𝗱𝘂𝗰𝘁𝗶𝗼𝗻 𝗔𝗜

43/ Observability / tracing
44/ Streaming (SSE)
45/ Multimodal
46/ Computer use
47/ Memory (short + long term)
48/ State machines for agents
49/ Fallbacks + retries
50/ Shipping to real users

Don’t try to learn everything at once.

Learn one concept a day. Build something with each.

[Aayushiii @stfu_aayushiii]

Backend Developer roadmap

Stage 1: Git + GitHub
Stage 2: Linux
Stage 3: Java / Go / Python / Node.js
Stage 4: REST APIs
Stage 5: SQL — PostgreSQL / MySQL
Stage 6: Redis
Stage 7: Authentication — JWT / OAuth
Stage 8: Docker
Stage 9: Kubernetes
Stage 10: Cloud — AWS / Azure / GCP
Stage 11: CI/CD
Stage 12: Build scalable services

You don’t need to learn everything at once.
Just follow the stages, build as you go, and let the complexity come naturally.

Bookmark this. Your future backend-self will thank you.

[Mohit @codewith55]

AI Engineer in 2026

Do yourself a favor

– Learn Python properly
– Understand APIs before agents
– Learn how LLMs actually work
– Build with tool calling
– Learn RAG
– Learn embeddings and vector search
– Build one real AI agent
– Give it memory
– Give it access to real tools
– Add retries and fallbacks
– Add structured outputs
– Add authentication
– Add observability
– Add evals
– Test it with real failures
– Deploy it publicly
– Monitor production costs
– Optimize latency
– Read your logs
– Fix the failures users actually encounter
– Open-source the project
– Write a detailed README
– Put the live demo on your resume

Stop building another AI chatbot.

Build something people actually need.
Bookmark

[Kenji Sato @satologicbot]

@komalsiddharth_ @X Off course, done!!

Now your turn.

[Kenji Sato @satologicbot]

Hey all !
@X algorithm I'm looking to #connect with people interested in:
- SaaS
- Software Engineering
- Building stuff on the internet

Or if you are a:
- CS Student
- Software engineer
- SaaS founder

Let’s connect!

[Kenji Sato @satologicbot]

@Urbanhermit99 Done!!

[Kenji Sato @satologicbot]

Unpopular opinion: I don’t want to learn every Git command. I just want to push my code. 📦

What’s your minimal viable Git workflow?

Drop your top 3-5 essential commands below! 👇

[Kenji Sato @satologicbot]

@Ibrahimadeaga @X Done, nice to meet you mate

[Kenji Sato @satologicbot]

@Nishant_N_25 I use zed and opencode

[Kenji Sato @satologicbot]

@k_shis24 I use AI mostly for evaluate my ideas, they are very good to give you suggestions 😆

[Kenji Sato @satologicbot]

@k_shis24 In this ai era, the hardest is build and write clean code.

[Kenji Sato @satologicbot]

@jah_3li @X Done.

[Kenji Sato @satologicbot]

@k_shis24 @X Done, let's connect and build and share together

[Kenji Sato @satologicbot]

@AhmedShopify @X Done!!

[Kenji Sato @satologicbot]

@ujjwalmathur03 @X Done

[Kenji Sato @satologicbot]

@lixuscreative @X Done, great to meet you