Quit Smoking

Quit Smoking (previously Smoke Free Days) is the Better Health quit-smoking companion and the successor to the Stoptober app.

The app follows the standard pattern.

---

Architecture Overview

graph TD;
    User[Mobile App]
    ALB[Application Load Balancer]
    Backend[ECS - Quit Smoking CMS]
    NHSLogin[ECS - NHS Login Backend]
    RDS[Aurora PostgreSQL]
    Redis[Elasticache Redis]
    MediaCloudfront[Static assets Cloudfront]
    MediaS3[S3 Media Bucket]
    NHSAuth[NHS Login / PDS APIs]

    User --> ALB --> Backend --> RDS
    User --> MediaCloudfront --> MediaS3
    Backend --> MediaS3
    ALB --> NHSLogin --> RDS
    NHSLogin --> Redis
    NHSLogin --> NHSAuth

---

Components

Applications

• Repo: smoke-free-days-iaas – Django CMS mobile client.
• Repo: quit-smoking-backend – FastAPI service that handles NHS login flows and syncs data. It also caches JWT tokens tokens in Redis.

Infrastructure as Code (IaC)

• Repo: smoke-free-days-iac – Terraform code for the infrastructure.

---

Environments

Environment	URL	Notes
Production	https://smokefreedays-prod.phedigital.co.uk	NHS login served from https://prd.quitsmoking.betterhealthapps.com.
Staging	https://smokefreedays-staging.phedigital.co.uk	Mirrors prod services; NHS login available at https://uat.quitsmoking.betterhealthapps.com.
Dev	https://smokefreedays-dev.phedigital.co.uk	First landing-zone account; NHS login endpoints at https://dev.quitsmoking.betterhealthapps.com.

---

DNS Overview

Two DNS hierarchies are involved:

1. phedigital.co.uk (phe-prd account) delegates smokefreedays-<env>.phedigital.co.uk to the individual accounts, where the ALB aliases and ACM certificates live.
2. betterhealthapps.com (also phe-prd) delegates <env>.quitsmoking.betterhealthapps.com so the NHS login backend can expose a friendly hostname.

Subdomains:

• smokefreedays-dev.phedigital.co.uk / -staging / -prod – Primary ALB entrypoints for each environment.
• dev.quitsmoking.betterhealthapps.com / staging / prod – NHS Login backend endpoints.

graph TD
  subgraph PHE_PRD[phe-prd account]
    PHE[phedigital.co.uk]
    BHA[betterhealthapps.com]
  end

  subgraph DEV_ACC[dev account]
    DEV_API[smokefreedays-dev.phedigital.co.uk]
    DEV_NHS[dev.quitsmoking.betterhealthapps.com]
    ALB_DEV[ALB - dev]
  end

  subgraph STG_ACC[staging account]
    STG_API[smokefreedays-staging.phedigital.co.uk]
    STG_NHS[staging.quitsmoking.betterhealthapps.com]
    ALB_STG[ALB - staging]
  end

  subgraph PRD_ACC[prd account]
    PRD_API[smokefreedays-prod.phedigital.co.uk]
    PRD_NHS[prod.quitsmoking.betterhealthapps.com]
    ALB_PRD[ALB - prod]
  end

  PHE -->|NS| DEV_API
  PHE -->|NS| STG_API
  PHE -->|NS| PRD_API

  BHA -->|NS| DEV_NHS
  BHA -->|NS| STG_NHS
  BHA -->|NS| PRD_NHS

  DEV_API --> ALB_DEV
  DEV_NHS --> ALB_DEV

  STG_API --> ALB_STG
  STG_NHS --> ALB_STG

  PRD_API --> ALB_PRD
  PRD_NHS --> ALB_PRD

If any hosted zone is recreated, be sure to refresh the glue/NS records in the phe-prd root zones so the delegation chain stays healthy.