senior loop
No auto-renewal · Pay manually

Pay for the months
you're prepping.

Most senior loops are over in 8–12 weeks. Pay then, stop when you're done.

Monthly
$19
/ month

For active prep cycles. No auto-renewal.

  • ✓Unlock the full catalog for 30 days
  • ✓Senior-tier AI grading on every review
  • ✓Multi-language exercises where available
  • ✓Scores and attempt history saved forever
  • ✓Stop paying when you're done prepping
RECOMMENDED
Quarterly
$25
/ quarter
$57Save $32 · 56% off

Covers most senior prep cycles end to end.

  • ✓Unlock the full catalog for 90 days
  • ✓Everything in Monthly
  • ✓Get every new exercise and deep dive added during your quarter

48-hour full refund if you've completed fewer than 3 graded exercises · full policy

No auto-renewal

Pay manually each cycle. No silent charges, no cancellation maze when you land the offer.

48-hour refund

Full refund if you request within 48 hours and have finished fewer than 3 graded exercises. No questions asked.

5 languages

Most exercises support Go, Kotlin, Python, Java, and C#. Each card shows the languages that are available now.

01—What's in the catalog

Exactly what's live right now.

No vague promises. Here's the specific content your subscription unlocks.

Code Review
3 free12 paid
15 PRs

Hand-authored PRs across payments, distributed systems, API design, security, and performance. AI-graded against a senior-engineer rubric.

Bug Hunt
3 free7 paid
10 exercises

Broken codebases, failing tests, real log excerpts. Find the root cause, fix it, compare against the canonical solution.

Design It
2 free5 pro
7 problems

System design problems in fixed parts: requirements, APIs, architecture, core mechanism, extended features, security, and scalability. Ticket booking, ride dispatch, payments ledger, multi-tenancy, observability. Graded against a rubric.

Build It
1 free4 paid
5 problems

Production systems built in stages: wallet, payments, inventory, jobs, notifications. Each stage tightens the constraints. The late stages are the senior filter.

Deep Dives
17 free33 pro
50 topics

Kafka, idempotency, Raft, distributed locks, rate limiting, consistent hashing. The tradeoffs and failure modes that short guides skip.

03—Not ready to commit?

Start free. No card required.

3 code reviews, 3 debug exercises, both Design It problems, and 17 Deep Dives, free, no commitment.

Start free →Read the Deep Dives first →

Questions worth answering honestly.

Try the free exercises first. If you buy a plan and want a refund, request it within 48 hours and before you complete 3 graded exercise submissions. We refund the full amount. Full terms are on the Cancellation & Refund Policy page.

General course platforms teach many topics. Senior Loop focuses only on hands-on senior backend practice: code review, production debugging, low-level and system design, and technical tradeoffs. Feedback compares your work with explicit answer keys.

Each PR has a hand-written bug list with severity and category. Claude AI compares your inline comments to that list. The score shows what was planted, not what an LLM happens to invent that day.

Your submissions and scores stay available. Paid catalog items lock again until you buy access again. Free items stay free.

Yes. New catalog items are included while your access is active: 90 days on Quarterly or 30 days on Monthly.

Not yet. Contact us if you want to sponsor 5 or more engineers. We can send a private invoice for now, and we will build the team plan when there is demand.