Tech Debt Log: Drop — Fintech Payment App
Tech Debt Log: Drop — Fintech Payment App
Project: Drop — Remittance + QR Payments Version: 1.0 Date: 2026-02-23 Author: John (AI Director) Status: Approved Reviewers: Alem Bašić (CEO)
Document History
| Version | Date | Author | Changes |
|---|---|---|---|
| 0.1 | 2026-02-23 | John | Initial tech debt log — Phase 0/0.5 items captured |
1. Tech Debt Philosophy
Technical debt is not inherently bad. Sometimes taking on debt is the right business decision (shipping faster to meet a deadline). The problem is unacknowledged and unmanaged debt.
This log exists to:
- Make invisible debt visible
- Enable informed decisions about when to repay debt
- Track the "interest" — how debt is slowing the team down
- Demonstrate to stakeholders that quality is actively managed
Debt Entry Trigger: Any time you make a technical shortcut, write a workaround, defer a refactor, skip a test, or make a "we'll fix this later" comment — add an entry here.
Drop-Specific Constraint: Drop is a fintech pass-through app under PSD2/AML regulation. Security and compliance debt (categories: Security, Design) get automatic P1 treatment regardless of impact score. No security debt survives more than 1 sprint without explicit CEO risk acceptance.
2. Summary Dashboard
| Metric | Current | Last Sprint | Trend |
|---|---|---|---|
| Total Items | 9 | 3 | ↑ |
| Open | 6 | 3 | ↑ |
| In Progress | 1 | 0 | ↑ |
| Resolved | 2 | 0 | ↑ |
| Critical / High (P1/P2) | 3 | 2 | → |
| Debt in current sprint | 1 | 0 | ↑ |
| Avg age of open items (days) | 14 | 14 | → |
| Debt resolved this sprint | 2 | 0 | ↑ |
Sprint Debt Budget: 20% of sprint capacity allocated to debt reduction (Phase 0.5 security hardening sprint exceeded this — security debt is P1 mandatory)
2. Tech Debt Categories
| Category | Description | Common Causes | Detection Method |
|---|---|---|---|
| Design | Architectural shortcuts, wrong abstractions, poor separation of concerns | Time pressure, evolving requirements | Code review, architecture review |
| Code Quality | Duplication, high complexity, poor naming, missing documentation | Speed over quality, lack of standards | Static analysis, code review |
| Infrastructure | Manual processes, missing monitoring, config drift, single points of failure | Growth outpacing ops maturity | Ops review, incident postmortems |
| Documentation | Missing or outdated technical docs, undocumented decisions, no onboarding guide | Documentation deferred, never caught up | New team member feedback, ops incidents |
| Dependency | Outdated libraries, deprecated APIs, unmaintained packages, version conflicts | Insufficient update cadence | Automated scan (npm audit) |
| Testing | Low coverage, flaky tests, missing integration tests, untested edge cases | Speed over quality | Coverage reports, incident analysis |
| Security | Known vulnerabilities not yet patched, security shortcuts taken | Urgency, lack of security knowledge | Security scan, CVE alerts |
| Performance | Known bottlenecks, inefficient queries, N+1 problems, no caching | Optimizations deferred | api-benchmarks.test.ts, load tests |
3. Impact Assessment Methodology
3.1 Impact Score (1–10)
| Score | Impact Level | Effect on Team/Business |
|---|---|---|
| 1–2 | Negligible | Cosmetic; no measurable effect on velocity or product |
| 3–4 | Minor | Slightly slows specific tasks; <5% velocity impact |
| 5–6 | Moderate | Slows multiple tasks; 5–15% velocity impact; occasional bugs |
| 7–8 | High | Significantly slows development; 15–30% velocity impact; recurring bugs |
| 9–10 | Critical | Blocks progress; >30% velocity impact; high risk of production incidents |
3.2 Effort to Fix (Story Points)
| Size | Points | Typical Scope |
|---|---|---|
| XS | 1 | Single line / config change |
| S | 2–3 | Single function / component refactor |
| M | 5–8 | Module-level changes; cross-cutting update |
| L | 13 | Multi-module refactoring; architecture change |
| XL | 21+ | Major refactor; break into sub-tasks first |
3.3 Priority Calculation
Priority = Impact Score × (1 / Effort) — High impact, low effort = P1
| Priority | Criteria | Sprint Allocation Target |
|---|---|---|
| P1 — Critical | Impact ≥ 8 OR blocks release OR any Security debt | Schedule within 1 sprint |
| P2 — High | Impact 6–7 | Schedule within 2 sprints |
| P3 — Medium | Impact 4–5 | Schedule within 4 sprints |
| P4 — Low | Impact ≤ 3 | Schedule when convenient |
4. Tech Debt Register
| ID | Description | Category | Introduced | Impact (1-10) | Effort | Priority | Owner | Status | Target Resolution | Review Date | Notes |
|---|---|---|---|---|---|---|---|---|---|---|---|
| TD-001 | SQLite has ~200 concurrent write limit. Under load, users may experience database is locked errors. Migration to PostgreSQL (Phase 1) is the full fix. |
Performance | Phase 0 | 8 | L | P1 | John | Open | Phase 1 launch | 2026-03-01 | NFR-S02 documents this. SQLite WAL mode mitigates but does not eliminate. Blocks production scale. |
| TD-002 | BaaS integration mocked via NEXT_PUBLIC_SERVICE_MODE=mock. No real SpareBank1 or Swan connection. All transactions are simulated. |
Design | Phase 0 | 10 | XL | P1 | John | Open | Phase 2 (BaaS partner confirmed) | 2026-03-01 | Blocks real money movement. BaaS partner pitch in progress. Cannot launch for real users until resolved. |
| TD-003 | KYC integration uses mock Sumsub. User identity verification is not real — any user can pass KYC in dev/staging. | Security | Phase 0 | 10 | L | P1 | John | Open | Phase 2 (Sumsub live integration) | 2026-03-01 | Blocks regulatory compliance. MUST be live before real user onboarding. Sumsub account manager contact transferred to John. |
| TD-004 | In-memory rate limiting (Node process memory) resets on server restart. Was Phase 0 implementation. | Security | Phase 0 | 7 | M | P1 | Builder Agent | Resolved | Phase 0.5 (resolved) | 2026-02-23 | RESOLVED in Phase 0.5 — replaced with DB-backed rate limiting using rate_limit_requests table. Per-user + per-IP persistence survives restarts. |
| TD-005 | No bcrypt password length limit — malicious users could submit 10,000-character passwords and trigger bcrypt DoS (bcrypt has O(n) cost on input length). | Security | Phase 0 | 7 | XS | P1 | Builder Agent | Resolved | Phase 0.5 (resolved) | 2026-02-23 | RESOLVED in Phase 0.5 — 1,000-character max input validation added in Zod schema before bcrypt. Regression test added. |
| TD-006 | Exchange rates are static seed data. No real rate feed from external provider. Rates in db/seeds/rates.sql do not auto-update. |
Design | Phase 0 | 6 | M | P2 | John | Open | Phase 2 | 2026-04-01 | Acceptable for MVP/demo. Phase 2 requires live rate feed (e.g., Open Exchange Rates API or Wise API). |
| TD-007 | BankID integration fully mocked. Age verification (≥18) and Norwegian residency checks use mock data only. | Security | Phase 0 | 9 | L | P1 | John | Open | Phase 1 or Phase 2 | 2026-03-01 | Regulatory requirement. BankID = mandatory per Norwegian PSD2 + AML. Cannot serve real users without it. Finanstilsynet registration in progress. |
| TD-008 | No structured logging / APM in place. console.log used for debug output in some modules. No Fly.io metrics integration beyond basic health check. |
Infrastructure | Phase 0 | 5 | M | P3 | John | Open | Phase 1 | 2026-04-01 | Low risk for MVP/demo. Phase 1 needs structured logging (e.g., Pino) + Fly.io metrics + Sentry error tracking. |
| TD-009 | Cards feature has no real card partner integration. Feature is behind CARDS_ENABLED=false flag — cards data is mocked, no real card issuing. |
Design | Phase 0 | 3 | XL | P4 | John | Open | Phase 3+ | 2026-06-01 | Low priority. Cards are explicitly Phase 3. Feature flag prevents exposure. No action needed for Phase 0.5 or Phase 1. |
Status Values: Open | In Progress | Resolved | Accepted (deferred) | Won't Fix (justified)
5. Prioritization Framework
5.1 Cost of Delay Analysis
| ID | Description | Cost Per Sprint (velocity loss %) | Number of Sprints Open | Accumulated Cost |
|---|---|---|---|---|
| TD-001 | SQLite concurrent limit | ~5% (affects test reliability under concurrency) | 1 | ~5% velocity |
| TD-002 | Mock BaaS | Blocks real revenue (100% blocker for live transactions) | 1 | Cannot launch |
| TD-003 | Mock KYC | Blocks regulatory compliance (100% blocker for real users) | 1 | Cannot launch |
| TD-007 | Mock BankID | Blocks age verification + AML compliance (100% blocker) | 1 | Cannot launch |
5.2 Debt Payoff Prioritization
When multiple P3 items compete for sprint capacity, use:
- Quick wins first — Impact ≥ 5 AND Effort ≤ S (high ROI)
- Blocker debt — Any item that blocks a planned feature or regulatory milestone
- Aging debt — Items open > 3 sprints get auto-elevated one priority
- Security debt — Always scheduled within 1 sprint regardless of impact score
Drop Rule: TD-002, TD-003, TD-007 (BaaS, KYC, BankID) are NOT fixed by code changes alone — they require confirmed external partners. Track separately as business dependencies, not engineering tasks.
6. Sprint Debt Allocation Guidelines
| Team Velocity | Debt Budget (20%) | Recommended Items to Schedule |
|---|---|---|
| 20 points/sprint (AI agents) | 4 points | 1–2 S items or 1 M item |
| 40 points/sprint | 8 points | 2–3 S items or 1 M item |
| 60 points/sprint | 12 points | 1 L item or 2 M items |
Sprint Debt Review (each sprint planning):
- John (AI Director) reviews open debt register (15 min)
- Select debt items based on budget and priority
- Add selected items to sprint backlog as technical tasks in Mission Control
- Update status of in-progress items
7. Debt Reduction Tracking
| Sprint | Debt Items Added | Debt Items Resolved | Net Change | Running Total Open |
|---|---|---|---|---|
| Phase 0 | 9 | 0 | +9 | 9 |
| Phase 0.5 | 0 | 2 (TD-004, TD-005) | -2 | 7 |
| Phase 1 | TBD | TBD (TD-001, TD-008 targets) | TBD | TBD |
Debt Trend: DECREASING (Phase 0.5 resolved 2 security items; 3 blockers are external business dependencies, not engineering debt)
8. Trend Analysis
8.1 Debt by Category (Phase 0 → Phase 0.5)
| Category | Items Added | Items Resolved | Net |
|---|---|---|---|
| Design | 3 (TD-002, TD-006, TD-009) | 0 | +3 |
| Security | 4 (TD-003, TD-004, TD-005, TD-007) | 2 (TD-004, TD-005) | +2 |
| Infrastructure | 1 (TD-008) | 0 | +1 |
| Performance | 1 (TD-001) | 0 | +1 |
| Code Quality | 0 | 0 | 0 |
| Testing | 0 | 0 | 0 |
| Documentation | 0 | 0 | 0 |
| Dependency | 0 | 0 | 0 |
8.2 Root Cause Analysis
Dominant category this quarter: Security + Design (MVP shortcuts) Suspected root cause: MVP phase deliberately chose mock integrations (BaaS, KYC, BankID) to ship working architecture without blocked external partners. This is intentional, managed debt — not negligence. Proposed systemic fix: Business dependency tracking separate from engineering debt. TD-002/003/007 are tracked in the ROADMAP.md as Phase 2 blockers and require Alem Bašić (CEO) partner decisions, not engineering sprints.
9. Resolved / Accepted Debt Archive
| ID | Description | Resolution | Resolution Date | Sprint | Resolved By |
|---|---|---|---|---|---|
| TD-004 | In-memory rate limiting resets on restart | Replaced with DB-backed rate_limit_requests table; persistent across restarts |
2026-02-23 | Phase 0.5 | Builder Agent |
| TD-005 | No password length limit — bcrypt DoS vector | Added Zod max(1000) validation before bcrypt hash; regression test in auth.test.ts |
2026-02-23 | Phase 0.5 | Builder Agent |
Related Documents
Approval
| Role | Name | Date | Signature |
|---|---|---|---|
| Author | John (AI Director) | 2026-02-23 | Approved (AI) |
| Tech Lead | John | 2026-02-23 | Approved |
| CEO (Alem) | Alem Bašić | TBD |
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