Technology Decision Guide

Technology Decision Guide

Decision frameworks and comparison matrices for common technology choices.

Decision Frameworks Index

1. Database Selection
2. Caching Strategy
3. Message Queue Selection
4. Authentication Strategy
5. Frontend Framework Selection
6. Cloud Provider Selection
7. API Style Selection

1. Database Selection

SQL vs NoSQL Decision Matrix

Database Type Selection

Relational (SQL):

Document (NoSQL):

Key-Value:

Wide-Column:

Time-Series:

Search:

Quick Decision Flow

Start
  │
  ├─ Need ACID transactions? ──Yes──► PostgreSQL/MySQL
  │
  ├─ Flexible schema needed? ──Yes──► MongoDB
  │
  ├─ Write-heavy (>50K/sec)? ──Yes──► Cassandra/ScyllaDB
  │
  ├─ Key-value access only? ──Yes──► Redis/DynamoDB
  │
  ├─ Time-series data? ──Yes──► TimescaleDB/InfluxDB
  │
  ├─ Full-text search? ──Yes──► Elasticsearch
  │
  └─ Default ──────────────────────► PostgreSQL

2. Caching Strategy

Cache Type Selection

Cache Technology Selection

Cache Patterns

Cache-Aside (Lazy Loading):

Read:
1. Check cache
2. If miss, read from DB
3. Store in cache
4. Return data

Write:
1. Write to DB
2. Invalidate cache

Write-Through:

Write:
1. Write to cache
2. Cache writes to DB
3. Return success

Read:
1. Read from cache (always hit)

TTL Guidelines:

3. Message Queue Selection

Queue Technology Comparison

Decision Matrix

When to Use Each

RabbitMQ:

• Complex routing logic (topic, fanout, headers)
• Request/reply patterns
• Priority queues
• Message acknowledgment critical

Kafka:

• Event sourcing
• High throughput requirements (>50K messages/sec)
• Message replay needed
• Stream processing
• Log aggregation

SQS:

• AWS-native applications
• Simple queue semantics
• Serverless architectures
• Don't want to manage infrastructure

Redis Streams:

• Already using Redis
• Moderate throughput
• Simple streaming needs
• Real-time features

4. Authentication Strategy

Method Selection

JWT vs Sessions

OAuth 2.0 Flow Selection

Avoid: Implicit flow (deprecated), Resource Owner Password (legacy only)

Token Lifetimes

5. Frontend Framework Selection

Framework Comparison

Decision Matrix

Meta-Framework Selection

When to Use SSR vs SPA vs SSG

6. Cloud Provider Selection

Provider Comparison

Decision Factors

Multi-Cloud Considerations

Go multi-cloud when:

• Regulatory requirements mandate it
• Specific service (e.g., GCP BigQuery) is best-in-class
• Negotiating leverage with vendors

Stay single-cloud when:

• Team is small
• Want to minimize complexity
• Deep integration needed

Service Mapping

7. API Style Selection

REST vs GraphQL vs gRPC

Decision Matrix

When to Choose Each

Choose REST when:

• Building public APIs
• Need HTTP caching
• Simple CRUD operations
• Team experienced with REST

Choose GraphQL when:

• Multiple clients with different data needs
• Rapid frontend iteration
• Complex, nested data relationships
• Want to reduce API calls

Choose gRPC when:

• Service-to-service communication
• Performance critical
• Streaming required
• Strong typing important

API Versioning Strategies

Recommendation: URL path versioning for public APIs, header versioning for internal.

Quick Reference