Publishing to Microsoft Store: MSIX, Certification, CI/CD

Developers often face certification rejection due to an invalid manifest or icons. The error The package manifest is not valid in WACK is a typical problem even for experienced teams. Add another complexity: the app must run correctly on different architectures (x86, x64, ARM64) and versions of Windows 10/11. Incorrect binding to a specific build is a common cause of WACK failure. We help navigate this path in 3–5 days—from MSIX packaging to turnkey publication. Pinpoint your case and we’ll prepare your app for release.

Microsoft Store supports three formats: packaged MSIX (Win32), UWP, and PWA. MSIX ensures clean installation and removal without traces. Electron and other cross-platform frameworks are published via MSIX—this allows using the full Win32 API without rewriting on WinRT.

Publication formats in Microsoft Store

How to package an Electron app into MSIX?

electron-builder can build MSIX directly. Example configuration:

# electron-builder.yml
win:
  target:
    - target: nsis
    - target: msix
  icon: build/icon.ico

msix:
  applicationId:  com.company.AppName
  backgroundColor: "#transparent"
  displayName:    "App Name"
  publisherDisplayName: "Company Name"
  identityName:  "CompanyName.AppName"

npx electron-builder --win msix

Signing the package requires a developer certificate from a Trusted CA (DigiCert, GlobalSign) or a certificate from Partner Center. Self-signed certificates are not accepted. We use automatic signing via CSC_LINK and CSC_KEY_PASSWORD in CI.

Why MSIX is the preferred format for the Store?

MSIX provides an isolated environment, guarantees correct removal and updates through the Store. Unlike UWP, MSIX packages can use Win32 API, so existing apps do not require a full rewrite. The format is certified by WACK, which checks compliance with Microsoft requirements. WACK errors are the main reason for rejection, so we pay special attention to preliminary verification.

A real case: reducing certification time from 2 weeks to 3 days

On a recent project for an Electron-based analytics tool, the client had failed WACK three times due to incorrect icon sizes and a mismatched publisher in the manifest. We analyzed the package, rebuilt it with correct manifests, generated proper icons, and pre-ran WACK locally. The fix took one day, and the app passed certification on the first resubmission. The entire process—from initial analysis to Store publishing—took three days.

How to pass WACK certification on the first try?

Before uploading, always run WACK locally:

& "C:\Program Files (x86)\Windows Kits\10\App Certification Kit\appcert.exe" `
  test -apppackagepath .\AppName.msix -reportoutputpath .\report.xml

WACK checks: valid manifest, no forbidden APIs, correct icons (required Square44x44, Square150x150, StoreLogo 300x300). Check the Publisher in the manifest: it must match the certificate. Our experience—5+ years in publishing Windows apps, over 30 successful Store releases. We guarantee passing WACK on the first attempt.

What if WACK gives an error?

Registration in Partner Center

1. Register a developer account (one-time fee).
2. Create a new app: Partner Center → Apps → New product.
3. Reserve the name and fill in metadata: description, screenshots (minimum 3, resolution from 1366×768), category, age rating.
4. Set the pricing model (free or paid product).

Filling in metadata is critical: incorrect age rating or wrong category leads to rejection. We recommend entrusting this work to our specialists.

Automating update publication

Use GitHub Actions with the microsoft/store-submission-action. Example workflow:

- name: Build MSIX
  run: npx electron-builder --win msix
  env:
    CSC_LINK:         ${{ secrets.WIN_CERTIFICATE }}
    CSC_KEY_PASSWORD: ${{ secrets.WIN_CERTIFICATE_PWD }}

- name: Upload to Partner Center
  uses: microsoft/store-submission-action@v1
  with:
    seller-id:      ${{ secrets.MS_SELLER_ID }}
    product-id:     ${{ secrets.MS_PRODUCT_ID }}
    package-path:   dist/AppName.msix
    tenant-id:      ${{ secrets.MS_TENANT_ID }}
    client-id:      ${{ secrets.MS_CLIENT_ID }}
    client-secret:  ${{ secrets.MS_CLIENT_SECRET }}

After uploading, Microsoft performs moderation (1–3 business days). Updates go through faster—in 1–2 days. For GitLab CI, the configuration is similar—use the corresponding action or a shell script with Azure CLI.

What's included in the work?

• App analysis and format selection (MSIX, UWP, or PWA)
• MSIX package creation with correct manifest and icons
• WACK certification and error resolution
• Partner Center registration and metadata filling
• CI/CD setup for automatic publishing (GitHub Actions, GitLab CI)
• Guarantee of successful publication on the first attempt

Timeline

MSIX preparation, WACK certification, and first publication: 3–5 business days. For complex apps (with drivers, extensions), the timeline may extend to 7–10 days. The cost is calculated individually based on project complexity.

We have years of experience, with dozens of projects published in Microsoft Store. Our engineers hold Microsoft certifications and are ready to solve non-standard problems. Get a consultation—we’ll assess your project and propose the optimal path.

We regularly encounter a situation: "The site is not opening" at 3 a.m. — and it turns out that the VPS disk is full because nginx logs haven't been rotated for six months. Or the server went down under load on the day of an advertising campaign launch because the shared hosting had a limit of 50 concurrent connections. Setting up hosting and deployment is not about "where it's cheaper" but about what happens when something goes wrong. Our team helps avoid such incidents by designing infrastructure that accounts for real load patterns.

When to choose Vercel and Netlify?

Vercel is built for Next.js — deploy in one push, preview deployments for every PR, automatic CDN, Edge Functions, ISR without configuration. For frontend projects and JAMstack, it's the optimal choice: no operational overhead, time-to-deploy measured in minutes.

Real limitations: Vercel Serverless Functions run in us-east-1 by default (latency for Europe +80–100ms), Function timeout 300 seconds on Pro, Bandwidth 1TB/month on Pro. For heavy backend, you need workers or a separate server.

Netlify is closer to static sites and Edge Functions based on Deno Deploy. Build minutes are the main limitation on the free tier.

Why is Docker the foundation of predictable deployment?

"It works on my machine" — classic. Docker solves this through environment containerization. But a bad Dockerfile creates new problems.

A typical mistake: copying everything into the image without .dockerignore, resulting in an 800MB image instead of 80MB. node_modules inside the image weighs as much. Correct approach: multi-stage build.

FROM node:20-alpine AS builder
WORKDIR /app
COPY package*.json ./
RUN npm ci --only=production
COPY . .
RUN npm run build

FROM node:20-alpine AS runner
WORKDIR /app
COPY --from=builder /app/.next ./.next
COPY --from=builder /app/node_modules ./node_modules
COPY --from=builder /app/package.json ./package.json
EXPOSE 3000
CMD ["npm", "start"]

Final image: 180MB instead of 1.2GB. CI build time is reduced due to layer caching — if package.json hasn't changed, the layer with npm ci is taken from cache.

Docker Compose for local development and simple production scenarios: application + PostgreSQL + Redis in one configuration. For production on a single server, it's a perfectly viable option if there's no requirement for horizontal scaling.

More about containerization — Wikipedia: Docker.

How to set up Nginx as a reverse proxy?

Nginx in front of the application is standard for VPS and dedicated servers. Main functions: SSL termination, gzip, static files, rate limiting, upstream load balancing.

A configuration often done incorrectly: worker_processes auto — number of processes equals CPU count. worker_connections 1024 — that's 1024 per worker process. With 4 CPUs and 1024 connections = 4096 concurrent connections. For a high-traffic site, you need worker_connections 4096 and set keepalive_timeout 65.

For static assets with hash in the filename:

location ~* \.(js|css|woff2|png|webp)$ {
    expires 1y;
    add_header Cache-Control "public, immutable";
}

immutable tells the browser: don't revalidate this file even on hard refresh. This only works correctly with content-hashed filenames (which Vite/webpack do by default). Documentation — Wikipedia: Nginx.

AWS: flexibility and complexity

EC2 + Auto Scaling Group — classic for horizontal scaling. AMI with pre-installed application, Launch Template, ASG with min/desired/max instances, Application Load Balancer. When CPU > 70% for 3 minutes — scale out, when CPU < 30% for 15 minutes — scale in. Health check via ALB removes unhealthy instances from rotation.

ECS Fargate — containers without managing EC2. Deploy a Docker image, specify CPU/memory (512 CPU units = 0.5 vCPU, from 512MB memory), Fargate launches it. More expensive than Lambda, but no cold start and no timeout limitations. Suitable for long-running processes, WebSocket servers, heavy workers.

RDS for PostgreSQL with Multi-AZ: automatic failover in 1–2 minutes when primary fails. Read Replicas for scaling reads. RDS Proxy for connection pooling — Lambda functions cannot hold long-term connections, the proxy buffers this.

Kubernetes: when it is justified

K8s adds significant operational complexity. Justified when: multiple teams deploy independent services, fine-grained resource allocation per service is needed, canary deployments and blue/green without downtime are required.

AWS EKS, GKE, or managed k8s from Hetzner (cheaper). Helm charts for standard services. Horizontal Pod Autoscaler based on CPU and custom metrics (RPS via Prometheus).

For most startups and medium-sized projects, Kubernetes is overkill. ECS or Fly.io provide 80% of the capabilities with 20% of the operational complexity.

Monitoring and alerting

A server without monitoring is waiting for an incident. Minimal stack: Prometheus + Grafana (or Grafana Cloud for managed), alerting on disk > 80%, memory > 85%, CPU > 90% over 5 minutes, error rate > 1%. Uptime via Better Uptime or Upptime (self-hosted).

Logs: Loki + Grafana or CloudWatch Logs Insights. Structured JSON logs (winston, pino) are mandatory — otherwise, log searching becomes a pain.

What is included in hosting setup

• Audit of current infrastructure and load profiling
• Selection of target architecture (VPS, AWS, serverless, Kubernetes)
• Setting up CI/CD pipeline (GitHub Actions, GitLab CI) with automatic deployment
• IaC via Terraform or Pulumi (infrastructure as code)
• Configuration of Nginx, SSL certificates, HTTP/2, brotli
• Monitoring and alerting (Prometheus + Grafana, PagerDuty)
• Documentation of runbooks and team training

Additionally, contact us if you need migration from current hosting or integration with external services.

Work process

1. Audit of current infrastructure (2–5 days)
2. Selection of target architecture with load and budget justification (1–3 days)
3. Setting up CI/CD pipeline (GitHub Actions, GitLab CI) (2–5 days)
4. IaC via Terraform or Pulumi (3–10 days)
5. Setting up monitoring and alerting (2–5 days)
6. Documentation of runbooks and team training (1–3 days)

Our experience — 7 years on the market, over 50 projects, guarantee of operability after deployment.

Timeline

• Basic deployment on VPS with Docker + Nginx + CI/CD: 1–2 weeks.
• Setting up AWS infrastructure with Auto Scaling, RDS, CDN: 3–6 weeks.
• Migration to EKS from scratch: 6–12 weeks.
• Setting up Vercel/Netlify for JAMstack: 3–5 days.

The cost is calculated individually depending on complexity and scope of work. Get a consultation — we'll evaluate your architecture in one day.