A collection of small, self-contained scripts (primarily Python, plus Bash) that demonstrate key backend engineering concepts covered in the notes. Python scripts use only the standard library so no extra dependencies are needed.
- Python 3.8 or later
- Bash
Run any script directly:
cd scripts
python api_design/rest_api_example.py| Directory | Script | Topic |
|---|---|---|
api_design/ |
rest_api_example.py |
Minimal REST API server with CRUD endpoints |
api_design/ |
graphql_example.py |
GraphQL-like query engine with field selection |
api_design/ |
idempotency_example.py |
Idempotency keys for retry-safe POST operations |
api_design/ |
webhook_signature_example.py |
HMAC webhook signature verification for event authenticity |
api_design/ |
pagination_example.sh |
Offset/limit pagination walkthrough for large datasets |
api_design/ |
versioning_example.py |
API versioning strategies (URL path, header, query param) |
network_communications/ |
tcp_udp_example.py |
TCP vs UDP echo server/client comparison |
network_communications/ |
http_request_example.py |
HTTP methods, headers, and content types |
network_communications/ |
retry_backoff_example.sh |
Exponential-backoff retry loop for unstable outbound calls |
network_communications/ |
circuit_breaker_example.py |
Circuit breaker state transitions for flaky dependencies |
network_communications/ |
dns_resolver_example.py |
Simulated hierarchical DNS resolution with caching |
databases/ |
transaction_example.py |
SQLite transactions and ACID properties |
databases/ |
index_example.py |
Index performance and EXPLAIN QUERY PLAN |
databases/ |
connection_pool_example.py |
Fixed-size connection pool acquisition and exhaustion |
databases/ |
migration_example.py |
Schema migration versioning with SQLite |
caching/ |
lru_cache_example.py |
LRU cache implementation and eviction |
caching/ |
cache_strategies_example.py |
Write-through, write-back, and cache-aside patterns |
caching/ |
cache_warming_example.sh |
Cache warm-up of hot keys before traffic cutover |
caching/ |
ttl_cache_example.py |
TTL-based cache with automatic expiration |
data_formats/ |
format_conversion.py |
JSON, XML, and YAML conversion |
data_formats/ |
protocol_buffer_example.py |
Protocol-buffer-like binary serialization |
data_processing/ |
pub_sub_example.py |
In-process publish/subscribe broker |
data_processing/ |
batch_processing_example.py |
Batch processing pipeline with configurable batches |
data_processing/ |
dead_letter_queue_example.py |
Retry then route poison jobs to a DLQ |
data_processing/ |
stream_processing_example.py |
Sliding-window stream processing pipeline |
security/ |
hashing_example.py |
Password hashing, token generation |
security/ |
jwt_example.py |
JWT-like token creation and verification |
security/ |
rate_limiter_example.py |
Token-bucket request throttling with burst tolerance |
security/ |
api_key_rotation_example.sh |
Zero-downtime API key rotation sequence |
security/ |
encryption_example.py |
Symmetric encryption, key derivation, and HMAC integrity |
distributed_systems/ |
gossip_protocol_example.py |
Gossip protocol cluster simulation |
distributed_systems/ |
vector_clock_example.py |
Vector clock causality tracking |
distributed_systems/ |
quorum_example.py |
Quorum overlap checks for replicated data consistency |
distributed_systems/ |
consistent_hashing_example.py |
Consistent hashing ring for data partitioning |
distributed_systems/ |
leader_election_example.py |
Bully algorithm leader election simulation |
server_technologies/ |
load_balancer_example.py |
Load balancing strategy simulation |
server_technologies/ |
reverse_proxy_example.py |
Reverse proxy routing by path prefix |
server_technologies/ |
nginx_log_parse_example.sh |
Parse access logs to count requests and 5xx errors |
server_technologies/ |
middleware_chain_example.py |
Middleware request pipeline with logging, auth, and CORS |
deployment/ |
health_check_example.py |
Health-check and readiness endpoints |
deployment/ |
rolling_deploy_example.py |
Rolling deployment simulation |
deployment/ |
rolling_restart_example.sh |
Rolling restart sequence with health-check gating |
deployment/ |
blue_green_switch_example.sh |
Blue/green deployment traffic switch workflow |
deployment/ |
canary_deploy_example.py |
Canary deployment with traffic shifting and auto-rollback |