SLA Report

SLA Report

Project: Bilko Version: 0.1 Date: 2026-02-23 Author: Ops Architect Status: Draft (Template — fill in monthly) Reviewers: Tech Lead, Alem Bašić

Document History

Version	Date	Author	Changes
0.1	2026-02-23	Ops Architect	Initial draft

---

INSTRUCTIONS

Generate monthly SLA reports by the 5th business day of the following month. File location: docs/operations/sla-reports/SLA-YYYY-MM.md

---

SLA Report: [Month YYYY]

Reporting Period: YYYY-MM-01 to YYYY-MM-[last day] Report Date: YYYY-MM-DD Prepared by: Ops Architect

---

1. SLA Summary

Service Level Objectives (SLOs)

SLO	Target	Actual	Status
API availability	≥ 99.5% / month	X.XX%	✅ / ❌
API P95 response time	< 500ms	XXXms	✅ / ❌
API error rate (5xx)	< 0.5%	X.XX%	✅ / ❌
Frontend availability	≥ 99.9% / month	X.XX%	✅ / ❌
Uptime (combined)	≥ 99.5% / month	X.XX%	✅ / ❌

SLO Calculation

API Availability = (Total minutes in month - Downtime minutes) / Total minutes × 100

Total minutes in month (28 days) = 40,320
Total minutes in month (31 days) = 44,640

Allowed downtime at 99.5%:
- 28-day month: 201.6 minutes = ~3h 22min
- 31-day month: 223.2 minutes = ~3h 43min

---

2. Uptime Metrics

API (api.bilko.io)

Metric	Value
Measured uptime	X.XX%
Total downtime	X minutes
Number of incidents	X
Longest outage	X minutes

Frontend (bilko.io)

Metric	Value
Measured uptime	X.XX%
Total downtime	X minutes
Number of incidents	X

Source: BetterStack uptime monitoring (1-min check interval)

---

3. Performance Metrics

API Response Times

Metric	Target	Week 1	Week 2	Week 3	Week 4	Month Avg
P50	< 100ms
P95	< 500ms
P99	< 1000ms

Critical Endpoint Performance

Endpoint	P95 Target	P95 Actual	Status
POST /api/v1/invoices	< 500ms	XXXms	✅ / ❌
GET /api/v1/invoices	< 200ms	XXXms	✅ / ❌
GET /api/v1/reports/vat	< 3000ms	XXXms	✅ / ❌
POST /api/v1/auth/login	< 300ms	XXXms	✅ / ❌

Source: Railway metrics + Sentry performance monitoring

---

4. Error Metrics

Error Rate by Week

Week	Total Requests	5xx Errors	Error Rate	Status
Week 1			X.XX%
Week 2			X.XX%
Week 3			X.XX%
Week 4			X.XX%
Month			X.XX%

Top Errors (Sentry)

#	Error	Count	Affected Users	Status
1	[Error message]	X	X	Fixed / Investigating
2
3

---

5. Incidents This Month

Incident ID	Date	Duration	Severity	Root Cause	Resolved
INC-YYYY-MM-DD-001	YYYY-MM-DD	X min	P0/P1/P2	[Short description]	Yes

Total downtime from incidents: X minutes P0 incidents: X (target: 0) P1 incidents: X (target: < 2/month)

---

6. Financial Data Integrity (Monthly Verification)

Required: Verify no financial data corruption occurred this month.

Check	Method	Result
Double-entry balance	SQL: SUM(debits) = SUM(credits) per org	✅ Balanced / ❌ Issues found
Invoice total accuracy	SQL: total = subtotal + tax - discount	✅ Accurate / ❌ Issues found
VAT calculation accuracy	Spot-check 10 random invoices	✅ Accurate / ❌ Issues found
No orphaned transactions	SQL: all transactions have debit+credit	✅ Clean / ❌ Issues found

Verification queries run on: YYYY-MM-DD Verified by: [Name]

-- Monthly double-entry balance verification
SELECT
  o.name as organization_name,
  SUM(CASE WHEN te.type = 'debit' THEN te.amount ELSE 0 END) as total_debits,
  SUM(CASE WHEN te.type = 'credit' THEN te.amount ELSE 0 END) as total_credits,
  ABS(SUM(CASE WHEN te.type = 'debit' THEN te.amount ELSE -te.amount END)) as imbalance
FROM transaction_entries te
JOIN transactions t ON t.id = te."transactionId"
JOIN organizations o ON o.id = t."organizationId"
WHERE t.created_at >= DATE_TRUNC('month', CURRENT_DATE)
  AND t.created_at < DATE_TRUNC('month', CURRENT_DATE) + INTERVAL '1 month'
GROUP BY o.id, o.name
HAVING ABS(SUM(CASE WHEN te.type = 'debit' THEN te.amount ELSE -te.amount END)) > 0.0001
ORDER BY imbalance DESC;
-- Expected: 0 rows (all organizations balanced)

---

7. Infrastructure Metrics

Railway (Backend + Database)

Resource	Average	Peak	Trend
API CPU	X%	X%	Stable / Growing / Decreasing
API Memory	XMB	XMB	Stable / Growing / Decreasing
DB Connections	X avg	X peak	Stable / Growing
DB Storage	XGB	—	+X GB this month

Vercel (Frontend)

Metric	Value
Total page views	X
Unique visitors	X
Average LCP	Xms
Average CLS	X

---

8. Cost Report

Service	Budget	Actual	Variance
Railway (API + DB)	€20	€XX	+/-€XX
Vercel	€0	€XX	+/-€XX
Cloudflare R2	€1	€XX	+/-€XX
SendGrid	€0	€XX	+/-€XX
Total	€21	€XX	+/-€XX

---

9. SLA Trending

Month	API Uptime	P95 Latency	Error Rate	Incidents
[Previous -2]	—	—	—	—
[Previous -1]	—	—	—	—
[This month]	X.XX%	XXXms	X.XX%	X

---

10. Action Items from This Report

#	Issue	Action	Owner	Due
1	[Issue]	[Action]	[Owner]	YYYY-MM-DD

---

Approval

Role	Name	Date	Signature
Author	Ops Architect
Reviewer	Alem Bašić