# DeepSeek V4 Pro on iac-bench 2026-10

> Source: <https://www.massdriver.cloud/blogs/iac-bench-2026-10-deepseek-v4-pro-0813>
> Published: 2026-11-04 00:00:00+00:00

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How DeepSeek V4 Pro did on iac-bench 2026-10: an overall composite of 69.2, scores per fixture, strengths, weaknesses and the patterns in its OpenTofu modules.

| Developer | DeepSeek | 
| API identifier | `deepseek/deepseek-v4-pro-0813` | 
| Access | OpenRouter | 
| Weights | Open | 
| List price (USD / M tokens, in / out) | 0.66 / 1.98 (OpenRouter, 2026-10-23) | 
| Evaluated | 2026-10-22 (generation) · 2026-10-23 (judge) | 
| Attempts | 9 (3 fixtures × 3 samples) | 
| **Overall composite** | **69.2** (95% CI 64.4–79.3) | 
| Rank | 8 of 10 (95% rank interval 6–9) | 
| Mechanical only / judge only | 69.5 (rank 8) / 67.5 (rank 9) | 
| Failed gates · insecure attempts | 0/9 · 5/9 | 
| Estimated cost, all 9 attempts | $0.88 | 

DeepSeek V4 Pro is close to the leading group on S3 (G001, median 82) and falls well behind on Cloud SQL and App Service. All 9 of its modules planned. Five of the 9 had a security finding, each caused by a security setting exposed as an input or left at an insecure provider default.

Its most distinctive weakness is documentation that describes behavior the code does not
implement. The judge scored *Documentation* 0 in all six of its Cloud SQL and App Service
attempts.

| Fixture | Composite median (range) | Rubric median | Expertise | Judge median | ✗ gate | ⚠ security | Median inputs | Median output tokens | Median time | Median cost | 
|---|---|---|---|---|---|---|---|---|---|---|
| G001 · S3 | 82.5 (69.6–82.6) | 0.791 | 4/7 | 84.2 | 0/3 | 1/3 ( `H1` ) | 8 | 27,086 | 432 s | $0.087 | 
| G002 · Cloud SQL | 62.1 (60.9–73.8) | 0.641 | 4/9 | 65.8 | 0/3 | 2/3 ( `H1` ,`H2` ) | 22 | 14,092 | 192 s | $0.097 | 
| G003 · App Service | 63.2 (61.4–81.8) | 0.708 | 2/5 | 52.6 | 0/3 | 2/3 ( `H1` ,`H2` ) | 21 | 19,960 | 493 s | $0.102 | 

Rubric items not at full credit, counted over attempts that planned: G001: `A5` 1/3, `B1` 2/3, `H1` 1/3, `H9` 2/3, `H12` 3/3, `H13` 3/3, `H15` 1/3; G002: `A2` 1/3, `A3` 2/3, `A8` 1/3, `B1` 3/3, `H1` 2/3, `H2` 1/3, `H5` 1/3, `H6` 1/3, `H9` 3/3, `H11` 2/3; G003: `A4` 1/3, `A6` 1/3, `A7` 2/3, `B1` 1/3, `H1` 1/3, `H2` 2/3, `H3` 1/3, `H7` 1/3. Definitions are in [Scoring criteria](https://www.massdriver.cloud/blogs/iac-bench-2026-10-scoring-criteria).

`var.block_public_access` (`H1`).` ipv4_enabled` is an input. In one it defaults to `true`, so
the defaults plan has a public IP, while the description says "Private-only
regardless of this flag" (`require_ssl = false` maps to
unencrypted connections (`H2`).` https_only` an input (`staging_traffic` input documented to route traffic, which only feeds an output;`prevent_destroy = var.deletion_protection` in 3/3 Cloud SQL
attempts, duplicating the native `deletion_protection` attribute. `zone`, `allocated_ip_range`,
`service_tag`).`_tmp_prod.tf` and `_full_test.tfvars`, and a pinned
`azurerm ~> 3.0` with deprecated arguments in one attempt.
`G002/deepseek-v4-pro-0813-e3/main.tf` lines 30–38

```
    ip_configuration {
      ipv4_enabled    = var.ipv4_enabled
      private_network = var.network

      allocated_ip_range = var.private_ip_allocated_range

      # TLS posture on the (opt-in) public path. Private path traffic never
      # leaves the VPC, but SSL is still enforced end-to-end for defense in depth.
      ssl_mode = var.require_ssl ? "TRUSTED_CLIENT_CERTIFICATE_REQUIRED" : "ALLOW_UNENCRYPTED_AND_ENCRYPTED"
```

The comment says SSL is enforced end to end, and the next line lets a caller turn it off. Public IP is also an input.

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