diff --git a/.circleci/config.yml b/.circleci/config.yml
deleted file mode 100644
index a812d6c8..00000000
--- a/.circleci/config.yml
+++ /dev/null
@@ -1,20 +0,0 @@
-version: 2
-jobs:
-  build:
-    docker:
-      - image: circleci/python:3.6
-    steps:
-      - checkout
-      - restore_cache:
-          key: deps1-{{ .Branch }}-{{ checksum "requirements_ci.txt" }}
-      - run:
-          command: |
-            python3 -m pip install tox
-      - run:
-          name: Running tests
-          command: |
-            tox
-      - save_cache:
-          key: deps1-{{ .Branch }}-{{ checksum "requirements_ci.txt" }}
-          paths:
-            - ".tox"
diff --git a/.github/workflows/python-package-pypi.yml b/.github/workflows/python-package-pypi.yml
new file mode 100644
index 00000000..f75de2d3
--- /dev/null
+++ b/.github/workflows/python-package-pypi.yml
@@ -0,0 +1,49 @@
+name: PyPI
+
+on:
+  release:
+    types: [published]
+
+permissions:
+  contents: read
+
+jobs:
+
+  release-build:
+    runs-on: ubuntu-latest
+
+    steps:
+      - uses: actions/checkout@v4
+
+      - uses: actions/setup-python@v5
+        with:
+          python-version: "3.10"
+
+      - name: install packages
+        run: pip install build twine
+      - name: build release package
+        run: python -m build
+
+      - name: upload windows dists
+        uses: actions/upload-artifact@v4
+        with:
+          name: release-dists
+          path: dist/
+
+  pypi-publish:
+    environment: publish
+    runs-on: ubuntu-latest
+    needs:
+      - release-build
+    permissions:
+      id-token: write
+
+    steps:
+      - name: Retrieve release distributions
+        uses: actions/download-artifact@v4
+        with:
+          name: release-dists
+          path: dist/
+
+      - name: Publish release distributions to PyPI
+        uses: pypa/gh-action-pypi-publish@release/v1
diff --git a/.github/workflows/python-package-tests.yml b/.github/workflows/python-package-tests.yml
new file mode 100644
index 00000000..2570a658
--- /dev/null
+++ b/.github/workflows/python-package-tests.yml
@@ -0,0 +1,26 @@
+name: tests
+
+on: [push, workflow_dispatch]
+
+jobs:
+  tests:
+
+    runs-on: ubuntu-latest
+    strategy:
+      matrix:
+        python: ["3.10"]
+
+    steps:
+      - uses: actions/checkout@v4
+      - name: Setup Python
+        uses: actions/setup-python@v5
+        with:
+          python-version: ${{ matrix.python }}
+      - name: Install tox
+        run: pip install tox
+      - name: Run tox
+        run: tox
+      - name: Upload coverage reports to Codecov
+        uses: codecov/codecov-action@v4.0.1
+        with:
+          token: ${{ secrets.CODECOV_TOKEN }}
diff --git a/.github/workflows/pythonpublish.yml b/.github/workflows/pythonpublish.yml
deleted file mode 100644
index b143a530..00000000
--- a/.github/workflows/pythonpublish.yml
+++ /dev/null
@@ -1,26 +0,0 @@
-name: Upload Python Package
-
-on:
-  release:
-    types: [created]
-
-jobs:
-  deploy:
-    runs-on: ubuntu-latest
-    steps:
-    - uses: actions/checkout@v2
-    - name: Set up Python
-      uses: actions/setup-python@v1
-      with:
-        python-version: '3.x'
-    - name: Install dependencies
-      run: |
-        python -m pip install --upgrade pip
-        pip install setuptools wheel twine
-    - name: Build and publish
-      env:
-        TWINE_USERNAME: ${{ secrets.PYPI_USERNAME }}
-        TWINE_PASSWORD: ${{ secrets.PYPI_PASSWORD }}
-      run: |
-        python setup.py sdist bdist_wheel
-        twine upload dist/*
diff --git a/.travis.yml b/.travis.yml
deleted file mode 100644
index dfacf00c..00000000
--- a/.travis.yml
+++ /dev/null
@@ -1,12 +0,0 @@
-language: python
-python:
-  - "3.6"
-# command to install dependencies
-install:
-  - pip install tox
-# command to run tests
-script:
-  - tox
-# commants to deploy
-after_success:
-  - bash <(curl -s https://codecov.io/bash)
diff --git a/CONTRIBUTING.md b/CONTRIBUTING.md
index 69126034..3a3ed401 100644
--- a/CONTRIBUTING.md
+++ b/CONTRIBUTING.md
@@ -103,8 +103,6 @@ resource. After initialising a new repository in an empty directory with `git in
 ```bash
 $ #if you use ssh:
 $ git remote add upstream git@github.com:tempoCollaboration/OQuPy.git
-$ #if you use https
-$ git remote add upstream https://github.com/tempoCollaboration/OQuPy.git
 
 $ git fetch upstream
 $ git checkout main
@@ -121,7 +119,7 @@ $ git push origin main
 ```
 
 ### 4. Setup your local environment
-As a development environment you will need `git`, `python3.6`, `pip3` and `tox`
+As a development environment you will need `git`, `python3.10`, `pip3` and `tox`
 installed.
 
 You need `git` to
@@ -130,7 +128,7 @@ changes to the repository, while `tox` allows you to run tests on the package
 in an virtual environment (to avoid that the result of the tests depends on the
 local setup). If you are unfamiliar with `git`,
 [this](https://swcarpentry.github.io/git-novice/) is a good place to start
-learning about it. Currently the code is tested against `python3.6`, which makes it
+learning about it. Currently the code is tested against `python3.10`, which makes it
 necessary to have this version of the python interpreter installed in the
 development environment.
 
@@ -176,8 +174,6 @@ added to the project, namely:
 
 * execute the tests that check the functionality of the package (with `pytest`)
 * test the coding style (with `pylint`)
-* check that the documentation can be generated (with `sphinx`)
-
 
 #### 7.1 test all
 You can run all three tests by simply running `tox` in your local clone of the repository:
@@ -187,20 +183,19 @@ $ tox
 This performs a bunch of tests. If they all pass, it will finish with something
 like:
 ```bash
-  py36: commands succeeded
-  style: commands succeeded
-  docs: commands succeeded
-  congratulations :)
+  pytest: OK (136.95=setup[30.37]+cmd[106.58] seconds)
+  pylint: OK (51.52=setup[25.93]+cmd[25.59] seconds)
+  congratulations :) (188.56 seconds)
 ```
 
 #### 7.2 test pytest only
-You can run the pytests on python3.6 with:
+You can run the pytests on python3.10 with:
 ```bash
-$ tox -e py36
+$ tox -e pytest
 ```
 or you can pick a specific test in `./tests` to run with:
 ```bash
-$ tox -e py36 coverage/api_test.py
+$ tox -e pytest coverage/api_test.py
 ```
 Here `coverage/api_test.py` is the path of the test file *relative to the tests
 directory* and the command must be run from the *base directory of the repository.*
@@ -209,18 +204,20 @@ directory* and the command must be run from the *base directory of the repositor
 This checks the code [code style](https://www.python.org/dev/peps/pep-0008/)
 with pylint:
 ```bash
-$ tox -e style
+$ tox -e pylint
 ```
 or you can check the style of a specific file in `./oqupy` with:
 ```bash
-$ tox -e style base_api.py
+$ tox -e pylint base_api.py
 ```
 where `base_api.py` is the path of the file *relative to the oqupy
 directory* and again this command must be run from the base directory 
 of the repository.
-[comment]: # (The reason for this is that tox prepends the path you pass as an argument with './oqupy/' when using the style command, and './tests/' when using the py36 command)
+[comment]: # (The reason for this is that tox prepends the path you pass as an
+argument with './oqupy/' when using the style command, and './tests/' when 
+using the py36 command)
 
-#### 7.4 test sphinx only
+#### 7.4 build the documentation
 This invokes a sphinx-build to build the HTML documentation
 ```bash
 $ tox -e docs
diff --git a/PULL_REQUEST_TEMPLATE.md b/PULL_REQUEST_TEMPLATE.md
index 79735546..47a62480 100644
--- a/PULL_REQUEST_TEMPLATE.md
+++ b/PULL_REQUEST_TEMPLATE.md
@@ -2,7 +2,7 @@
 
 This checklist serves as a guide for contributors and maintainers to assess
 whether a contribution can be merged into the main branch and thus serves
-to guarantee the quality of the package. Please also read the
+to guarantee the quality of the package. Please read the
 [contribution guideline](https://github.com/tempoCollaboration/OQuPy/blob/main/CONTRIBUTING.md).
 
 Before you submit a pull request, please go through this checklist once
@@ -18,13 +18,10 @@ type of your contribution.
 * [ ] The automated test are all positive:
   - [ ] `tox -e py36` (to run `pytest`) the code tests.
   - [ ] `tox -e style` (to run `pylint`) the [code style](https://www.python.org/dev/peps/pep-0008/) tests.
-  - [ ] `tox -e docs` (to run `sphinx`) generate the documentation.
 * [ ] Added test for changed/added code.
-* [ ] API code contributions include input checks (defensive code).
-* [ ] API code contributions include helpful error messages.
 * [ ] The documentation has been updated:
   - [ ] docstring for all new functions/methods/classes/modules.
   - [ ] consistent style of all docstrings.
   - [ ] for new modules: `/docs/pages/modules.rst` has been updated.
-  - [ ] for api contributions: `/docs/pages/api.rst` has been updated.
-  - [ ] for api contributions: tutorials and examples have been updated.
+  - [ ] for new functionality: `/docs/pages/api.rst` has been updated.
+  - [ ] for new functionality: tutorials and examples have been updated.
diff --git a/oqupy/backends/node_array.py b/oqupy/backends/node_array.py
index 7707cc5c..406262e2 100644
--- a/oqupy/backends/node_array.py
+++ b/oqupy/backends/node_array.py
@@ -112,7 +112,7 @@ def __str__(self) -> Text:
 
     def get_verbose_string(self):
         """Returns a verbose desciption of the NodeArray. """
-        ret = [self.__str__()]
+        ret = [str(self)]
         ret.append("\n")
         ret.append(f" rank = {self.rank}\n")
         ret.append(f" len = {len(self)}\n")
diff --git a/oqupy/helpers.py b/oqupy/helpers.py
index 0def27ac..9a1303cd 100644
--- a/oqupy/helpers.py
+++ b/oqupy/helpers.py
@@ -41,7 +41,7 @@ def plot_correlations_with_parameters(
     if parameters.add_correlation_time is None:
         add_time = 0.0
         infinity = False
-    elif parameters.add_correlation_time == np.infty:
+    elif parameters.add_correlation_time == np.inf:
         add_time = 0.0
         infinity = True
     else:
diff --git a/oqupy/system_dynamics.py b/oqupy/system_dynamics.py
index 6f54f9c8..0a4fa01d 100644
--- a/oqupy/system_dynamics.py
+++ b/oqupy/system_dynamics.py
@@ -16,6 +16,7 @@
 """
 
 from typing import List, Optional, Text, Tuple, Union
+import warnings
 
 from itertools import product
 import numpy as np
@@ -862,12 +863,12 @@ def compute_correlations_nt(
         dt_ = process_tensor.dt
     else:
         if (process_tensor.dt is not None) and (process_tensor.dt != dt):
-            UserWarning("Specified time step `dt` does not match `dt` " \
+            warnings.warn("Specified time step `dt` does not match `dt` " \
                 + "stored in the given process tensor " \
                 + f"({dt}!={process_tensor.dt}). " \
                 + "Using specified `dt`. " \
                 + "Don't specify `dt` to use the time step stored in the " \
-                + "process tensor.")
+                + "process tensor.", UserWarning)
         dt_ = dt
 
     #Check that lengths of the ops_order, ops_times and dip_ops lists are equal
@@ -892,7 +893,7 @@ def compute_correlations_nt(
 
     ret_correlations = np.empty(times_length, dtype=NpDtype)
     #This array will contain all correlations
-    ret_correlations[:] = np.NaN + 1.0j*np.NaN
+    ret_correlations[:] = np.nan + 1.0j*np.nan
 
 
     parameters = {
diff --git a/pylintrc b/pylintrc
index 5780168d..73b43fd7 100644
--- a/pylintrc
+++ b/pylintrc
@@ -54,79 +54,16 @@ confidence=
 # --enable=similarities". If you want to run only the classes checker, but have
 # no Warning level messages displayed, use"--disable=all --enable=classes
 # --disable=W"
-disable=print-statement,
-        parameter-unpacking,
-        unpacking-in-except,
-        old-raise-syntax,
-        backtick,
-        long-suffix,
-        old-ne-operator,
-        old-octal-literal,
-        import-star-module-level,
-        non-ascii-bytes-literal,
-        raw-checker-failed,
+disable=raw-checker-failed,
         bad-inline-option,
         locally-disabled,
-        locally-enabled,
         file-ignored,
         suppressed-message,
         useless-suppression,
         deprecated-pragma,
-        apply-builtin,
-        basestring-builtin,
-        buffer-builtin,
-        cmp-builtin,
-        coerce-builtin,
-        execfile-builtin,
-        file-builtin,
-        long-builtin,
-        raw_input-builtin,
-        reduce-builtin,
-        standarderror-builtin,
-        unicode-builtin,
-        xrange-builtin,
-        coerce-method,
-        delslice-method,
-        getslice-method,
-        setslice-method,
-        no-absolute-import,
-        old-division,
-        dict-iter-method,
-        dict-view-method,
-        next-method-called,
-        metaclass-assignment,
-        indexing-exception,
-        raising-string,
-        reload-builtin,
-        oct-method,
-        hex-method,
-        nonzero-method,
-        cmp-method,
-        input-builtin,
-        round-builtin,
-        intern-builtin,
-        unichr-builtin,
-        map-builtin-not-iterating,
-        zip-builtin-not-iterating,
-        range-builtin-not-iterating,
-        filter-builtin-not-iterating,
-        using-cmp-argument,
-        eq-without-hash,
-        div-method,
-        idiv-method,
-        rdiv-method,
-        exception-message-attribute,
-        invalid-str-codec,
-        sys-max-int,
-        bad-python3-import,
-        deprecated-string-function,
-        deprecated-str-translate-call,
-        deprecated-itertools-function,
-        deprecated-types-field,
-        next-method-defined,
-        dict-items-not-iterating,
-        dict-keys-not-iterating,
-        dict-values-not-iterating,
+        use-implicit-booleaness-not-comparison-to-string,
+        use-implicit-booleaness-not-comparison-to-zero,
+        use-symbolic-message-instead,
         super-init-not-called,            # GEFux: added by hand
         duplicate-code,                   # GEFux: added by hand
         too-many-statements,              # GEFux: added by hand
@@ -140,7 +77,9 @@ disable=print-statement,
         abstract-method,                  # GEFux: added for development
         consider-using-enumerate,         # GEFux: added by hand
         consider-using-f-string,          # GEFux: added for development
-		too-many-arguments,				  # piperfw: added for development (MF degeneracy)
+        too-many-arguments,               # piperfw: added for development
+        possibly-used-before-assignment,  # GEFux: added by hand
+        unnecessary-lambda-assignment     # GEFux: added by hand
 
 # Enable the message, report, category or checker with the given id(s). You can
 # either give multiple identifier separated by comma (,) or put this option
@@ -244,13 +183,6 @@ max-line-length=80 # GEFux
 # Maximum number of lines in a module
 max-module-lines=2000
 
-# List of optional constructs for which whitespace checking is disabled. `dict-
-# separator` is used to allow tabulation in dicts, etc.: {1  : 1,\n222: 2}.
-# `trailing-comma` allows a space between comma and closing bracket: (a, ).
-# `empty-line` allows space-only lines.
-no-space-check=trailing-comma,
-               dict-separator
-
 # Allow the body of a class to be on the same line as the declaration if body
 # contains single statement.
 single-line-class-stmt=no
@@ -555,4 +487,4 @@ valid-metaclass-classmethod-first-arg=mcs
 
 # Exceptions that will emit a warning when being caught. Defaults to
 # "Exception"
-overgeneral-exceptions=Exception
+overgeneral-exceptions=bultins.Exception
diff --git a/requirements.txt b/requirements.txt
index dd4b9569..fc7aca66 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -1,4 +1,4 @@
-numpy>=1.18.0
+numpy>=1.18,<2.0
 scipy>=1.4.0
 tensornetwork==0.4.3
 matplotlib>=3.0.0
diff --git a/requirements_ci.txt b/requirements_ci.txt
index 0e8fade6..5d73b0a0 100644
--- a/requirements_ci.txt
+++ b/requirements_ci.txt
@@ -1,16 +1,15 @@
-pytest
+pytest>=8.1.0
 pytest-cov
-pylint
+pylint>=3.1.0
 sphinx
 sphinx_rtd_theme
 ipython
-docutils==0.16
 setuptools
 wheel
-numpy>=1.18.0
+docutils==0.16
+numpy>=1.18,<2.0
 scipy>=1.4.0
 tensornetwork==0.4.3
 matplotlib>=3.0.0
-tox
 h5py>=3.1.0
 numdifftools>=0.9.41
diff --git a/setup.py b/setup.py
index eac976ae..708236b6 100644
--- a/setup.py
+++ b/setup.py
@@ -45,7 +45,7 @@
     url='http://github.com/tempoCollaboration/OQuPy',
     author='TEMPO Collaboration',
     author_email='tempo.collaboration@gmail.com',
-    python_requires=('>=3.6.0'),
+    python_requires=('>=3.10.0'),
     install_requires=requirements,
     license='Apache 2.0',
     description=short_description,
@@ -59,7 +59,7 @@
     packages=find_packages(exclude=['tests']),
     classifiers=[
         "Development Status :: 3 - Alpha",
-        "Programming Language :: Python :: 3.6",
+        "Programming Language :: Python :: 3.10",
         "License :: OSI Approved :: Apache Software License",
         "Operating System :: OS Independent",
     ]
diff --git a/tests/physics/tempo_superohmic_test.py b/tests/physics/tempo_superohmic_test.py
index 389640c2..fd89de23 100644
--- a/tests/physics/tempo_superohmic_test.py
+++ b/tests/physics/tempo_superohmic_test.py
@@ -70,7 +70,7 @@ def test_tensor_network_tempo_backend_E():
         dt=0.4,
         dkmax=2,
         epsrel=1.0e-5,
-        add_correlation_time=np.infty)
+        add_correlation_time=np.inf)
     tempo_E = oqupy.Tempo(
         system_E,
         bath_E,
@@ -87,7 +87,7 @@ def test_tensor_network_pt_tempo_backend_E():
         dt=0.4,
         dkmax=2,
         epsrel=1.0e-5,
-        add_correlation_time=np.infty)
+        add_correlation_time=np.inf)
     pt = oqupy.pt_tempo_compute(
         bath_E,
         start_time=t_start_E,
diff --git a/tox.ini b/tox.ini
index 72b28f7f..0bc3daf4 100644
--- a/tox.ini
+++ b/tox.ini
@@ -1,25 +1,26 @@
 [tox]
-minversion = 3.10.0
-envlist = py36, style, docs
+minversion = 4.14.0
+envlist = pytest, pylint
 
-[testenv:py36]
+[testenv:pytest]
 description = run pytests and make coverage report
+basepython = python3.10
 deps = -rrequirements_ci.txt
 commands =
     pytest --cov-report term-missing --cov=oqupy ./tests/{posargs}
     python -m coverage xml
 
-[testenv:style]
+[testenv:pylint]
 description = check code style with pylint
-basepython = python3.6
+basepython = python3.10
 deps = -rrequirements_ci.txt
 commands =
     pylint ./oqupy/{posargs}
 
 [testenv:docs]
 description = invoke sphinx-build to build the HTML docs
-basepython = python3.6
+basepython = python3.10
 deps = -rrequirements_ci.txt
 commands =
     sphinx-build -M html ./docs ./docs/_build
-;    sphinx-build -M latexpdf ./docs ./docs/_build
+