"Modernise" usually means: get off old patterns, adopt DX, migrate VF to LWC, replace Workflow/Process Builder with Flow, tighten security, improve test coverage, set up CI/CD.
Phase 1: Assessment (weeks 1-4)
- Inventory: every Apex class, trigger, flow, VF page, Workflow, Process Builder. Categorise by criticality and complexity.
- Code quality scan: PMD, Apex Static Analysis. Identify governor-limit risk, security issues, deprecated patterns.
- Test coverage audit: where's coverage thin? Which classes have 75% coverage but no real assertions?
- DX-readiness: convert org metadata to source format. Set up Git repo as a baseline.
- Stakeholder alignment: leadership buy-in, scope, timeline, success metrics.
Phase 2: Foundation (weeks 5-12)
- Set up CI/CD: PR validation against scratch orgs. PMD checks. Jest for LWC. This protects future work.
- Refactor critical classes: triggers without handlers, classes >1000 lines, anything with SOQL-in-loops.
- Improve test coverage to 80%+ with meaningful assertions on critical paths.
- Standards documentation: code style, branch policy, handler framework, naming conventions.
- Security baseline: Health Check, Field-Level Security audit, Permission Set audit.
Phase 3: Process Builder / Workflow Migration (months 3-9)
- Use Migrate to Flow tool for simple cases.
- Manual rewrite for complex.
- Test side-by-side in sandbox before flipping.
- Phase by object: simple ones first.
Phase 4: VF -> LWC migration (months 4-18)
- Inventory VF pages, prioritise by user impact.
- Start with high-traffic, low-complexity pages.
- Build component library — reusable LWC primitives that match the new design system.
- Coexist: Aura/VF and LWC live in the same app during transition.
Phase 5: Security hardening (ongoing)
- Move to Permission Set Groups; minimise Profile permissions.
- Enforce MFA / SSO.
- Tighten Sharing rules.
- Enable Lightning Web Security where possible.
Phase 6: Performance and scale (ongoing)
- Identify hot paths via Event Monitoring / debug logs.
- Convert Roll-Up Summaries on large objects to scheduled calculations where appropriate.
- Index audit (Setup -> Custom Indexes if available).
- Bulkify all long-running flows / triggers.
Phase 7: Tooling and DX (months 1-6)
- Migrate from Change Sets to Salesforce DX.
- VS Code as the standard editor.
- Set up scratch org-based feature branches.
- Document the new workflow.
Phase 8: Governance (ongoing)
- Code review process.
- Release calendar.
- Architectural decision records.
- Onboarding documentation for new devs.
Common challenges:
- Time pressure for new features. Modernisation can't pause feature work; carve out 20-30% capacity for tech debt continuously.
- "It's not broken, why fix it?" sentiment. Show concrete metrics: deploy time reduced, error rate dropped, developer onboarding faster.
- Knowledge gaps. Senior devs may not know LWC; pair / training as part of the plan.
- Org politics — different teams own different parts of the org; coordinate carefully.
Success metrics:
- Deploy time: hours -> minutes.
- PR merge cycle time: days -> hours.
- Apex test coverage: 75% -> 90%.
- Production error rate.
- Time to onboard a new dev: weeks -> days.
A 1-2 year modernisation is a major undertaking. Without leadership buy-in and continuous capacity, it stalls. With it, the gains compound — every month, code is faster to deploy, easier to change, safer to break.